OCANF / OceanaGold Corporation - SEC-arkiveringar, Årsredovisning, Fullmaktsutlåtande

OceanaGold Announces Additional High-Grade Drill Results at Haile

Exhibit 99.1 OceanaGold Announces Additional High-Grade Drill Results at Haile VANCOUVER, BC, May 12, 2026 /CNW/ - OceanaGold Corporation (TSX: OGC) (NYSE: OGC) ("OceanaGold" or the "Company") is pleased to announce high-grade results from its ongoing exploration and resource conversion drilling program at the Haile Gold Mine ("Haile") in the United States. Drilling Highlights (core length): Horse

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addres

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addres

Capital

Exhibit 99.2 First Quarter Overview • Safely and responsibly produced 130,100 ounces of gold and 3,200 tonnes of copper, as per plan. • All-In Sustaining Cost (“AISC”)† of $2,094 per ounce. • Record quarterly revenue of $715 million at a record average realized gold price of $4,894 per ounce. • EBITDA Margin† of 58%, net profit2 of $228 million and EPS of $1.01. • Record Operating Cash Flow of $38

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim Management Discussion and Analysis (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended 31 March 2026. 2

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Marius van Niekerk, EVP & Chief Financial Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim Management Discussion and Analysis (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended 31 March 2026.

OceanaGold Delivers Strong First Quarter with $255M of Free Cash Flow (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.5 OceanaGold Delivers Strong First Quarter with $255M of Free Cash Flow (All financial figures in United States dollars unless otherwise stated) • Produced 130,100 ounces of gold and 3,200 tonnes of copper, in line with the full year plan. • Delivered record revenue, record operating cash flow, and increased the cash balance by 30%. • Progressed growth projects and returned $77 million

The accompanying notes to the Condensed Interim Consolidated Financial Statements are an integral part of these financial statements.

Exhibit 99.1 OceanaGold Corporation Condensed Interim Consolidated Statements of Financial Position (in millions of United States dollars - unaudited) March 31 December 31 Notes 2026 2025 ASSETS Current assets Cash and cash equivalents $ 620.1 $ 476.5 Trade and other receivables 5 23.8 17.4 Inventories 6 223.2 218.1 Prepayments 14.7 19.8 Derivative financial assets - diesel hedges 10.0 – Total cur

FORM OF PROXY

Exhibit 99.3

Vote your shares in advance

Submission Proof - Form 6-K Exhibit 99.2 Letter to Shareholders Dear Shareholders, 2025 was an outstanding year of delivery aligned with our corporate strategy, which is to increase and sustain a higher value for OceanaGold shares. Across our portfolio, we delivered safe and responsible gold production, met our commitments to the market and achieved record financial results, all while continuing t

NOTICE OF AVAILABILITY

Exhibit 99.4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of May, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addres

Notice of 2026 Annual General and

Submission Proof - Form 6-K Exhibit 99.1 Notice of 2026 Annual General and Special Meeting of Shareholders We invite you to attend the Annual General and Special Meeting (Meeting) of the shareholders (Shareholders) of OceanaGold Corporation (Company or OceanaGold) that will be held virtually on: The Meeting will be held for the following purposes: 1. To receive and consider the audited consolidate

The accompanying notes to the Consolidated Financial Statements are an integral part of these financial statements.

Exhibit 99.1 Consolidated Financial Statements For the years ended: December 31, 2025 and 2024 Independent auditor’s report To the Shareholders of OceanaGold Corporation Our opinion In our opinion, the accompanying consolidated financial statements present fairly, in all material respects, the financial position of OceanaGold Corporation and its subsidiaries (together, the Company) as at December

Consent of Independent Auditor

Exhibit 99.2 Consent of Independent Auditor We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (File No. 333-294905) and Form 40-F (File No. 001-43215) of OceanaGold Corporation of our report dated February 18, 2026 relating to the financial statements of OceanaGold Corporation, which appears in Exhibit 99.1 of OceanaGold Corporation’s Current Report on

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Address of pr

Consent of Independent Auditor

Exhibit 99.3 Consent of Independent Auditor We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (File No. 333-294905) and Form 40-F (File No. 001-43215) of OceanaGold Corporation (the “Company”) of our report dated February 19, 2025 (except as to Note 11 which is as of February 18, 2026) relating to the consolidated financial statements as at and for the

(All financial figures in United States dollars unless otherwise stated)

Exhibit 99.1 OceanaGold Releases 2025 Sustainability Report (All financial figures in United States dollars unless otherwise stated) VANCOUVER, BC, April 29, 2026 /CNW/ - OceanaGold Corporation (TSX: OGC) (NYSE: OGC) ("OceanaGold" or the "Company") is pleased to publish its annual Sustainability Report for the year ended December 31, 2025. The report outlines OceanaGold's sustainability performanc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of April, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addr

OceanaGold Provides Notice of First Quarter 2026 Results, Conference Call, and 2026 Annual Meeting of the Shareholders

Exhibit 99.1 OceanaGold Provides Notice of First Quarter 2026 Results, Conference Call, and 2026 Annual Meeting of the Shareholders VANCOUVER, BC, April 16, 2026 /CNW/ - OceanaGold Corporation (TSX: OGC) (NYSE: OGC) ("OceanaGold" or the "Company") will release its operational and financial results for the first quarter of 2026 after market close on Wednesday, May 6, 2026. The results will be made

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of April, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addr

CONSENT

Exhibit 23.9 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Report ide

CONSENT

Exhibit 23.10 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Report ti

CONSENT

Exhibit 23.11 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Report ti

CONSENT

Exhibit 23.24 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of the report titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 (the “Expert Report”), originally prepared for the Company. The und

CONSENT

Exhibit 23.7 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). The undersigned understands that the Company wishes to make reference

OceanaGold Commences Trading on the New York Stock Exchange

Exhibit 99.1 OceanaGold Commences Trading on the New York Stock Exchange VANCOUVER, BC, April 7, 2026 /CNW/ - OceanaGold Corporation (TSX: OGC) (NYSE: OGC) ("OceanaGold" or the "Company") is pleased to announce the Company's common shares have commenced trading on the New York Stock Exchange ("NYSE") at market open today, Tuesday April 7, 2026, under the ticker symbol "OGC". Quotation of OceanaGol

CONSENT

Exhibit 23.21 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancast

CONSENT

Exhibit 23.16 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Report ti

CONSENT

Exhibit 23.12 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). The undersigned understands that the Company wishes to make reference

CONSENT

Exhibit 23.13 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Reports i

CONSENT

Exhibit 23.20 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancast

CONSENT

Exhibit 23.25 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 (the “Old Haile Expert Report”) and “NI 43-101 Technical R

CONSENT

Exhibit 23.19 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Report ti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of April, 2026 Commission File Number: 001-43215 OceanaGold Corporation (Translation of registrant's name into English) Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada (Addr

CONSENT

Exhibit 23.22 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancast

As filed with the Securities and Exchange Commission on April 7, 2026

As filed with the Securities and Exchange Commission on April 7, 2026 Registration No.

CONSENT

Exhibit 23.23 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancast

CONSENT

Exhibit 23.15 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Reports i

Table 1: Newly Registered Securities

Calculation of Filing Fee Tables S-8 OceanaGold Corp Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common shares, without par value Other 218,680,000 $ 218,680,000.

CERTIFICATE BUSINESS CORPORATIONS ACT

Exhibit 4.1 Number: BC0786321 CERTIFICATE OF INCORPORATION BUSINESS CORPORATIONS ACT I Hereby Certify that OCEANAGOLD CORPORATION was incorporated under the Business Corporations Act on March 22, 2007 at 04:48 PM Pacific Time. Issued under my hand at Victoria, British Columbia On March 22, 2007 /s/ RON TOWNSHEND RON TOWNSHEND Registrar of Companies Province of British Columbia Canada

CONSENT

Exhibit 23.17 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Reports i

CONSENT

Exhibit 23.18 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). The undersigned understands that the Company wishes to make reference

PROVINCE OF BRITISH COLUMBIA BUSINESS CORPORATIONS ACT ARTICLES OF OCEANAGOLD CORPORATION

Exhibit 4.2 Incorporation Number BC0786321 Translation of Name (if any) Effective Date June 15, 2007, as amended May 20, 2013 and June 4, 2025 PROVINCE OF BRITISH COLUMBIA BUSINESS CORPORATIONS ACT ARTICLES OF OCEANAGOLD CORPORATION TABLE OF CONTENTS Page PART 1 INTERPRETATION 1.1 Definitions 1 1.2 Business Corporations Act Definitions Apply 2 1.3 Interpretation Act Applies 2 1.4 Conflict in Defin

CONSENT

Exhibit 23.14 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the report titled “NI 4

Amended and Restated Performance Share Rights Plan for Designated Participants of OceanaGold Corporation and its Affiliates Adopted with effect as at 15 June 2012, as amended and restated on June 12, 2015, June 1, 2018, June 14, 2020, June 29, 2021,

Exhibit 4.3 Amended and Restated Performance Share Rights Plan for Designated Participants of OceanaGold Corporation and its Affiliates Adopted with effect as at 15 June 2012, as amended and restated on June 12, 2015, June 1, 2018, June 14, 2020, June 29, 2021, February 16, 2023 and April 18, 2024 OUR VALUES: CARE | RESPECT | INTEGRITY | PERFORMANCE | TEAMWORK Amended and Restated Performance Shar

CONSENT

Exhibit 23.8 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form S-8 of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form S-8 (as defined below). Additionally, the undersigned is an author of the Technical Reports id

ORDER

UNITED STATES OF AMERICA BEFORE THE SECURITIES AND EXCHANGE COMMISSION April 1, 2026 In the Matter of OceanaGold Corporation Suite 1020, 400 Burrard Street Vancouver, British Columbia V6C 3A6 Canada ORDER DECLARING REGISTRATION EFFECTIVE PURSUANT TO SECTION 12(d) OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED File No: 001-43215 OceanaGold Corporation has filed with the Commission and the New York Stock Exchange an application to register its Common Shares on the exchange, pursuant to Section 12(b) of the Securities Exchange Act of 1934.

NYSE CERTIFICATION

New York Stock Exchange 11 Wall Street New York, NY 10005 Tel: +1 212.656.3000 nyse.com March 31, 2026 Chief, Information Technology Securities and Exchange Commission Division of Corporate Finance 100 F Street, NE MS 3040 Washington, DC 20549 To whom it may concern: The New York Stock Exchange certifies its approval for listing and registration of the Common Shares, no par value of OCEANAGOLD COR

CONSENT

Exhibit 99.84 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancas

OceanaGold Reports Mineral Reserves and Resources for the Year Ended 2024

Exhibit 99.33 February 19, 2025 News Release OceanaGold Reports Mineral Reserves and Resources for the Year Ended 2024 (VANCOUVER) OceanaGold Corporation (TSX:OGC, OTCQX:OCANF) (“OceanaGold” or the “Company”) is pleased to provide its Mineral Reserves and Mineral Resources (“R&R”) statement for the year-ended December 31, 2024. Highlights •Mineral Reserves increased by 27% to 6.2 Moz Au net of min

OceanaGold Reports Voting Results from its 2025 Annual General and Special Meeting

Exhibit 99.41 June 4, 2025 News Release OceanaGold Reports Voting Results from its 2025 Annual General and Special Meeting (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCANF) (“OceanaGold” or the “Company”) is pleased to report the voting results from the Company's 2025 Annual General and Special Meeting of Shareholders (the "Annual Meeting") held today. A total of 538,458,035 common s

CONSENT

Exhibit 99.69 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

CONSENT

Exhibit 99.71 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

CONSENT

Exhibit 99.76 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

579,901 1

Exhibit 99.2 Annual Information Form For the year ended December 31, 2025 Date: March 27, 2026 Annual Information Form 2025 Table of Contents Introductory Notes 1 Date of Information 1 Cautionary Note Regarding Forward-Looking Information 1 Currency and Exchange Rate Information 3 Technical Information 3 Cautionary Note for United States Readers 5 Corporate Structure 6 Name, Address and Incorporat

Annual Information Form For the year ended December 31, 2024 Date: March 31, 2025

Exhibit 99.1 Annual Information Form For the year ended December 31, 2024 Date: March 31, 2025 www.oceanagold.com Table of Contents Introductory Notes 1 Date of Information 1 Cautionary Note Regarding Forward-Looking Information 1 Currency and Exchange Rate Information 2 Technical Information 2 Cautionary Note for United States Readers 4 Corporate Structure 5 Name, Address and Incorporation 5 Inte

The accompanying notes to the Consolidated Financial Statements are an integral part of these financial statements.

Exhibit 99.12 Consolidated Financial Statements For the years ended: December 31, 2025 and 2024 OceanaGold Corporation Consolidated Statements of Financial Position As at December 31(in millions of United States dollars) Notes 2025 2024 ASSETS Current assets Cash and cash equivalents $ 476.5 $ 193.5 Trade and other receivables 6 17.4 13.7 Inventories 7 218.1 239.5 Prepayments 19.8 18.6 Total curre

FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE

Exhibit 99.15 FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1.Review: I have reviewed the AIF, annual financial statements and annual MD&A, including, for greater certainty, all documents and information that are incorporated by reference in the AIF (together, the “annual filings”)

OceanaGold Provides Notice of Fourth Quarter and Full Year 2025 Results and Conference Call

Exhibit 99.52 NEWS RELEASE January 20, 2026 OceanaGold Provides Notice of Fourth Quarter and Full Year 2025 Results and Conference Call VANCOUVER, BC – OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) (“OceanaGold” or the “Company”) will release its operational and financial results for the fourth quarter and year ending December 31, 2025, after market close on Wednesday, February 18, 2026. The re

CONSENT

Exhibit 99.73 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). The undersigned understands that the Company wishes to make referen

CONSENT

Exhibit 99.75 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

CONSENT

Exhibit 99.86 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancas

CONSENT

Exhibit 99.87 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of the report titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 (the “Expert Report”), originally prepared for the Company. The un

OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND NINE MONTHS ENDED SEPTEMBER 30, 2025 AND 2024

Exhibit 99.9 OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND NINE MONTHS ENDED SEPTEMBER 30, 2025 AND 2024 OceanaGold Corporation Condensed Interim Consolidated Statements of Financial Position (in millions of United States dollars - unaudited) September 30 December 31 Notes 2025 2024 ASSETS Current assets Cash and cash equivalents $ 334.9 $ 193.5 Trade

Management’s Discussion and Analysis Third Quarter 2025 Results November 5, 2025

Exhibit 99.10 Management’s Discussion and Analysis Third Quarter 2025 Results November 5, 2025 Third Quarter Overview • Remain on track to deliver full year production, cost and capital guidance. • Safely and responsibly produced 103,500 ounces of gold and 3,100 tonnes of copper. • Waste stripping at Haile and Macraes is well advanced, with higher-grade ore from the open pits delivered in the thir

February 20, 2025

Exhibit 99.29 February 20, 2025 To: British Columbia Securities Commission Alberta Securities Commission Financial and Consumer Affairs Authority of Saskatchewan Manitoba Securities Commission Ontario Securities Commission Autorité des marchés financiers (Québec) Financial and Consumer Services Commission (New Brunswick) Nova Scotia Securities Commission Office of the Superintendent of Securities

February 20, 2025

Exhibit 99.31 February 20, 2025 To: British Columbia Securities Commission Alberta Securities Commission Financial and Consumer Affairs Authority of Saskatchewan Manitoba Securities Commission Ontario Securities Commission Autorité des marchés financiers (Québec) Financial and Consumer Services Commission (New Brunswick) Nova Scotia Securities Commission Office of the Superintendent of Securities

OceanaGold Announces New Discovery and Additional High-Grade Drill Results at Haile

Exhibit 99.36 February 24, 2025 News Release OceanaGold Announces New Discovery and Additional High-Grade Drill Results at Haile (VANCOUVER) OceanaGold Corporation (TSX: OGC; OTCQX:OCANF) (“OceanaGold” or the “Company”) is pleased to provide results from exploration and resource conversion drilling at the Haile Gold Mine (“Haile”) in the United States. Drill highlights include (core length): Pisce

OceanaGold Provides Notice of First Quarter 2025 Results and Conference Call, and Annual General and Special Meeting of

Exhibit 99.38 April 8, 2025 News Release OceanaGold Provides Notice of First Quarter 2025 Results and Conference Call, and Annual General and Special Meeting of Shareholders (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCANF) (“OceanaGold” or the “Company”) will release its operational and financial results for the first quarter of 2025 after market close on Wednesday, May 7, 2025. The

OceanaGold Reports First Quarter 2025 Operating & Financial Results (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.39 May 7, 2025 News Release OceanaGold Reports First Quarter 2025 Operating & Financial Results (All financial figures in United States dollars unless otherwise stated) •On track to deliver full year production, cost and capital investment guidance •Produced 117,400 ounces of gold at an All-In Sustaining Cost of $1,796 per ounce •Strong Free Cash Flow† of $69 million, zero debt, cash ba

CONSENT

Exhibit 99.70 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). The undersigned understands that the Company wishes to make referen

CONSENT

Exhibit 99.72 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

OceanaGold Receives Permit Approval for the Waihi North Project

Exhibit 99.51 December 18, 2025 News Release OceanaGold Receives Permit Approval for the Waihi North Project (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) ("OceanaGold" or the "Company") is pleased to announce that the Expert Panel appointed by the New Zealand government to consider permitting of the Waihi North Project (“WNP”) has released a final decision approving the project

FORM 13-502F1 CLASS 1 AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION

Exhibit 99.59 FORM 13-502F1 CLASS 1 AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION I, VAN NIEKERK, Marius , an officer of the reporting issuer noted below have examined this Form 13-502F1 (the Form) being submitted hereunder to the Ontario Securities Commission and certify that to my knowledge, having exercised reasonable diligence, the information provided in the Form

OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2025 AND 2024

Exhibit 99.7 OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2025 AND 2024 OceanaGold Corporation Condensed Interim Consolidated Statements of Financial Position (in millions of United States dollars - unaudited) June 30 December 31 Notes 2025 2024 ASSETS Current assets Cash and cash equivalents $ 298.7 $ 193.5 Trade and other

OCEANAGOLD CORPORATION CONSOLIDATED FINANCIAL STATEMENTS FOR THE YEARS ENDED DECEMBER 31, 2024 AND 2023

Exhibit 99.4 OCEANAGOLD CORPORATION CONSOLIDATED FINANCIAL STATEMENTS FOR THE YEARS ENDED DECEMBER 31, 2024 AND 2023 Independent auditor’s report To the Shareholders of OceanaGold Corporation Our opinion In our opinion, the accompanying consolidated financial statements present fairly, in all material respects, the financial position of OceanaGold Corporation and its subsidiaries (together, the Co

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL

Exhibit 99.20 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Marius van Niekerk, EVP & Chief Financial Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended June 30, 2025. 2. No misrepresentations: Bas

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL

Exhibit 99.22 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Marius van Niekerk, EVP & Chief Financial Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended September 30, 2025. 2. No misrepresentations

OceanaGold Provides Notice of Third Quarter 2025 Results and Conference Call

Exhibit 99.48 October 7, 2025 News Release OceanaGold Provides Notice of Third Quarter 2025 Results and Conference Call (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) (“OceanaGold” or the “Company”) will release its operational and financial results for the third quarter of 2025 after market close on Wednesday, November 5, 2025. The results will be made available on the Company’s

OceanaGold Submits WNP Application for Fast-track Approval and Reports Additional High-Grade Mineralization at Wharekirauponga

Exhibit 99.37 March 4, 2025 News Release OceanaGold Submits WNP Application for Fast-track Approval and Reports Additional High-Grade Mineralization at Wharekirauponga (VANCOUVER) OceanaGold Corporation (TSX: OGC; OTCQX: OCANF) (“OceanaGold” or the “Company”) announces results from five drillholes from the ongoing exploration and resource conversion program at Wharekirauponga, New Zealand. The Com

OceanaGold Extends High-Grade Mineralization at Wharekirauponga and Receives Draft Decision and Conditions to Approve the Waihi North Project

Exhibit 99.50 November 25, 2025 News Release OceanaGold Extends High-Grade Mineralization at Wharekirauponga and Receives Draft Decision and Conditions to Approve the Waihi North Project (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) ("OceanaGold" or the "Company") announces results from ten drill holes from the ongoing exploration and resource conversion program at Wharekiraupon

Released: March 27, 2026

Exhibit 99.62 NI 43-101 Technical Report Macraes Operation, Otago, New Zealand Effective Date: December 31, 2025 Report Date: March 27, 2026 Report Prepared by: OCEANAGOLD Suite 1020, 400 Burrard Street Vancouver, BC V6C 3A6 Canada Signed by Qualified Persons: Matthew Grant PhD Applied Geology, MAIG, MAusIMM (OceanaGold Senior Geologist – Resource Development). Knowell Madambi, BSc Eng (Hons) Mini

Management’s Discussion and Analysis Fourth Quarter and Full Year 2024 Results February 19, 2025

Exhibit 99.3 Management’s Discussion and Analysis Fourth Quarter and Full Year 2024 Results February 19, 2025 Highlights Overview •Fourth quarter production of 150,900 ounces of gold and 3,100 tonnes of copper, an increase in gold production of 12% from the prior quarter. •Record quarterly and annual production at Haile and best quarterly production at Waihi since production commenced at Martha Un

Management’s Discussion and Analysis Second Quarter 2025 Results August 6, 2025

Exhibit 99.8 Management’s Discussion and Analysis Second Quarter 2025 Results August 6, 2025 Second Quarter Overview •On track to deliver full year production, cost and capital guidance. •Safely and responsibly produced 119,500 ounces of gold and 3,700 tonnes of copper. •All-In Sustaining Cost (“AISC”)† of $2,027 per ounce in the quarter, resulting in $1,915 year to date, at the low-end of guidanc

FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE

Exhibit 99.16 FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE I, Marius van Niekerk, Executive Vice President & Chief Financial Officer, OceanaGold Corporation, certify the following: 1.Review: I have reviewed the AIF, annual financial statements and annual MD&A, including, for greater certainty, all documents and information that are incorporated by reference in the AIF (together,

Notice of Meeting

Exhibit 99.23 Notice of Meeting and Management Information Circular dated April 23, 2025 in respect of the Annual General and Special Meeting of Shareholders to be held on Wednesday June 4, 2025 at 9:00am (Canada Eastern Standard Time) Important information – This is an important document that should be read in its entirety. If you do not understand it, you should consult your professional adviser

FORM 13-501F1 CLASS 1 REPORTING ISSUERS AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION

Exhibit 99.58 Note: [01 Mar 2017] – The following is a consolidation of 13-501F1. It incorporates amendments to this document that came into effect on March 1, 2017. This consolidation is provided for your convenience and should not be relied on as authoritative. FORM 13-501F1 CLASS 1 REPORTING ISSUERS AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION I, VAN NIEKERK, Mari

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING A. Name of issuer or person filing (“Filer”): OceanaGold Corporation B. (1) This is (check one): ☒ An original filing for the Filer. ☐ An amended filing for the Filer. (2) Check the following box if you are filing the Form F-X in paper in accordance with Regulation S-T Rul

Report of Voting Results Section 11.3 of National Instrument 51-102

Exhibit 99.25 Report of Voting Results Section 11.3 of National Instrument 51-102 In accordance with Section 11.3 of National Instrument 51-102 – Continuous Disclosure Obligations, this report briefly describes the matters voted upon and the outcome of voting at the Annual General and Special Meeting of Shareholders of OceanaGold Corporation (the “Company”) held on June 4, 2025. Total Shares Voted

OCEANAGOLD CORPORATION Amended and Restated Schedule B – Updated Articles to the OceanaGold Corporation 2025 Management Information Circular dated April 23, 2025

Exhibit 99.26 OCEANAGOLD CORPORATION Amended and Restated Schedule B – Updated Articles to the OceanaGold Corporation 2025 Management Information Circular dated April 23, 2025 filed pursuant to the news release of OceanaGold Corporation dated May 7, 2025 Incorporation Number BC0786321 Translation of Name (if any) Effective Date June 15, 2007, as amended May 20, 2013 and [•] PROVINCE OF BRITISH COL

February 20, 2025

Exhibit 99.30 February 20, 2025 To: British Columbia Securities Commission Alberta Securities Commission Financial and Consumer Affairs Authority of Saskatchewan Manitoba Securities Commission Ontario Securities Commission Autorité des marchés financiers (Québec) Financial and Consumer Services Commission (New Brunswick) Nova Scotia Securities Commission Office of the Superintendent of Securities

OceanaGold Provides Notice of Fourth Quarter and Full Year 2024 Results and Conference Call

Exhibit 99.32 January 21, 2025 News Release OceanaGold Provides Notice of Fourth Quarter and Full Year 2024 Results and Conference Call (VANCOUVER) OceanaGold Corporation (TSX:OGC, OTCQX:OCANF) (“OceanaGold” or the “Company”) will release its operational and financial results for the fourth quarter and year ending December 31, 2024, after market close on Wednesday February 19, 2025. The results wi

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F (Check One) [X] Registration statement pursuant to Section 12 of the Securities Exchange Act of 1934 [ ] Annual report pursuant to Section 13(a) or 15(d) of the Securities Excha

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F (Check One) [X] Registration statement pursuant to Section 12 of the Securities Exchange Act of 1934 or [ ] Annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 For the fiscal year ended Commission file number OCEANAGOLD CORPORATION (Exact name of registrant as specified in its charter) Brit

FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE

Exhibit 99.13 FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the AIF, if any, annual financial statements and annual MD&A, including, for greater certainty, all documents and information that are incorporated by reference in the AIF (together, the "annual f

OceanaGold Announces Ongoing Exploration Success at Haile

Exhibit 99.47 September 11, 2025 News Release OceanaGold Announces Ongoing Exploration Success at Haile (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) ("OceanaGold" or the "Company") is pleased to announce positive results from its exploration and resource conversion drilling programs at the Haile Gold Mine (“Haile”) in the United States. Gerard Bond, President and CEO of OceanaG

CONSENT

Exhibit 99.82 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

CONSENT

Exhibit 99.74 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

OCEANAGOLD CORPORATION NOTICE OF CHANGE OF AUDITOR

Exhibit 99.28 OCEANAGOLD CORPORATION NOTICE OF CHANGE OF AUDITOR TO: PricewaterhouseCoopers ("PWC Australia") 2 Riverside Quay Southbank, VIC 3006 Australia AND TO: PricewaterhouseCoopers LLP ("PWC Canada") 250 Howe Strreet, Suite 1400 Vancouver, BC V6C 3S7 AND TO: Alberta Securities Commission British Columbia Securities Commission Manitoba Securities Commission Saskatchewan Financial Services Co

OceanaGold Releases 2024 Sustainability Report

Exhibit 99.40 May 21, 2025 News Release OceanaGold Releases 2024 Sustainability Report (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCANF) ("OceanaGold" or the "Company") is pleased to publish its annual Sustainability Report and related documents for the year ended December 31, 2024. Gerard Bond, President and CEO of OceanaGold, said “We made good progress on our sustainability commit

Measured & Indicated

Exhibit 99.63 NI 43-101 Technical Report – Didipio Mine, Luzon, Philippines Forward-Looking Information This report contains certain “forward-looking statements” and “forward-looking information” (collectively, “forward-looking statements”) within the meaning of applicable Canadian securities laws which may include, but is not limited to, statements with respect to: future financial and operating

OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS ENDED MARCH 31, 2025 AND 2024

Exhibit 99.5 OCEANAGOLD CORPORATION CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE MONTHS ENDED MARCH 31, 2025 AND 2024 OceanaGold Corporation Condensed Interim Consolidated Statements of Financial Position (in millions of United States dollars - unaudited) Notes March 31 2025 December 31 2024 ASSETS Current assets Cash and cash equivalents $ 227.6 $ 193.5 Trade and other receiv

FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE

Exhibit 99.14 FORM 52-109F1 CERTIFICATION OF ANNUAL FILINGS FULL CERTIFICATE I, Marius van Niekerk, Executive Vice President & Chief Financial Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the AIF, if any, annual financial statements and annual MD&A, including, for greater certainty, all documents and information that are incorporated by reference in the AIF (t

OceanaGold Reports Third Quarter 2025 Results (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.49 November 5, 2025 News Release OceanaGold Reports Third Quarter 2025 Results (All financial figures in United States dollars unless otherwise stated) • On track to deliver full year guidance with strong Q4 advancing as planned • Free Cash Flow† of $94 million with $335 million of cash and no debt at quarter end • Share buyback program increased by 75% to $175M, expected to be complete

CONSENT

Exhibit 99.68 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

OceanaGold Reports Mineral Reserves and Resources for the Year Ended 2025

Exhibit 99.54 NEWS RELEASE February 18, 2026 OceanaGold Reports Mineral Reserves and Resources for the Year Ended 2025 VANCOUVER, BC – OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) (“OceanaGold” or the “Company”) is pleased to provide its Mineral Reserves and Mineral Resources statement for the year ended December 31, 2025. Highlights •Total Mineral Reserves of 5.83 million ounces of gold (“Moz

OceanaGold Files Annual Information Form and Updated Technical Reports for Haile, Macraes and Didipio

Exhibit 99.55 NEWS RELEASE March 27, 2026 OceanaGold Files Annual Information Form and Updated Technical Reports for Haile, Macraes and Didipio VANCOUVER, BC – OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) (“OceanaGold” or the “Company”) announces that it has filed its Annual Information Form, along with updated technical reports prepared in accordance with National Instrument 43 – 101 – Standa

NI 43-101 Technical Report

Exhibit 99.60 NI 43-101 Technical Report Waihi District Pre-feasibility Study, New Zealand Effective Date: June 30, 2024 Report Date: December 11, 2024 Report Prepared by: OceanaGold Corporation Suite 1020, 400 Burrard Street Vancouver, BC V6C 3A6 Canada Signed by Qualified Persons: David Townsend, Assoc Deg (Surveying), GDip (Mining), MAusIMM CP (Min) (OceanaGold Mining Manager) Leroy Crawford-Fl

Consent of Independent Auditor

Exhibit 99.64 Consent of Independent Auditor We hereby consent to the incorporation by reference in this Registration Statement on Form 40-F of OceanaGold Corporation (the Company) of our report dated February 18, 2026, relating to the consolidated financial statements as at and for the year ended December 31, 2025, which appears in Exhibit 99.12 to this Registration Statement on Form 40-F. We als

Management’s Discussion and Analysis First Quarter 2025 Results May 7, 2025

Exhibit 99.6 Management’s Discussion and Analysis First Quarter 2025 Results May 7, 2025 First Quarter Overview • On track to deliver full year production, cost and capital guidance. • Safely and responsibly produced 117,400 ounces of gold and 3,400 tonnes of copper, both increased by 12% from the prior corresponding quarter. • All-In Sustaining Cost (“AISC”)† of $1,796 per ounce, below the full-y

Security Class

Exhibit 99.24 8th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com Security Class Holder Account Number Fold Form of Proxy - Annual General and Special Meeting to be held virtually on June 4, 2025 at 9:00 am (EDT) This Form of Proxy is solicited by and on behalf of Management. Notes to proxy 1.Every holder has the right to appoint some other person or company of their ch

FORM 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.27 FORM 51-102F3 MATERIAL CHANGE REPORT 1.Name and Address of Company OceanaGold Corporation (the "Company" or "OceanaGold") 400 Burrard St., Suite 1020 Vancouver British Columbia V6C 3A6 2.Date of Material Change June 23, 2025 3.News Release The news release issued with respect to the material change was disseminated through Newswire on June 19, 2025, and a copy was filed under the Com

OceanaGold Reports Record Quarterly Net Profit (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.46 August 6, 2025 News Release OceanaGold Reports Record Quarterly Net Profit (All financial figures in United States dollars unless otherwise stated) •Produced 119,500 ounces of gold and on track to deliver full year guidance •Record quarterly net profit of $118 million and record Adjusted EPS† of $0.51 •Free Cash Flow† of $120 million with $299 million of cash and no debt (VANCOUVER,

OceanaGold Achieves 2025 Guidance & Delivers Record Free Cash Flow (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.53 NEWS RELEASE February 18, 2026 OceanaGold Achieves 2025 Guidance & Delivers Record Free Cash Flow (All financial figures in United States dollars unless otherwise stated) •2025 production, AISC†, and capital all in line with Guidance •Record quarterly and annual financial performance, with $477M of cash and no debt at year end •2026 Guidance projects 12%1 increase in production at 7%

CONSENT

Exhibit 99.88 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 (the "Old Haile Expert Report") and “NI 43-101 Technical

Q4 2025

Exhibit 99.11 Management’s Discussion and Analysis Fourth Quarter and Full Year 2025 Results February 18, 2026 Highlights Overview •Full year 2025 production of 497,600 ounces of gold, above the mid-point of Guidance. •Produced 157,400 ounces of gold and 3,200 tonnes of copper in the fourth quarter, an increase in gold production of 52% from the prior quarter, with all four sites delivering an inc

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.17 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim Management Discussion and Analysis (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended 31 March 2025.

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.18 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Marius van Niekerk, EVP & Chief Financial Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the "interim filings") of OceanaGold Corporation (the "issuer") for the interim period ended 31 March 2025. 2. No misrepresentations: Bas

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.19 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim Management Discussion and Analysis of Financial Condition and Results of Operations (together, the "interim filings") of OceanaGold Corporation (the "issu

CONSENT

Exhibit 99.66 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

CONSENT

Exhibit 99.77 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the report titled “NI

CONSENT

Exhibit 99.78 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

CONSENT

Exhibit 99.79 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

CONSENT

Exhibit 99.83 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancas

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL

Exhibit 99.21 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Gerard Bond, President & Chief Executive Officer, OceanaGold Corporation, certify the following: 1. Review: I have reviewed the interim financial report and interim Management Discussion and Analysis of Financial Condition and Results of Operations (together, the "interim filings") of OceanaGold Corporation (the "issu

OceanaGold Extends Strike Length at Wharekirauponga

Exhibit 99.43 June 25, 2025 News Release OceanaGold Extends Strike Length at Wharekirauponga (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCANF) ("OceanaGold" or the "Company") announces results from seven drill holes from the ongoing exploration and resource conversion program at Wharekirauponga, located approximately 10 kilometres (“km”) to the north of the Company’s Waihi operation

OceanaGold Announces Renewal of Share Buyback

Exhibit 99.45 July 22, 2025 News Release OceanaGold Announces Renewal of Share Buyback (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCAND) (“OceanaGold” or the “Company”) announces it has received approval from the Toronto Stock Exchange (“TSX”) to renew its Normal Course Issuer Bid (“NCIB”), permitting the Company to buy back up to approximately 23 million common shares (“Common Share

Measured & Indicated

Exhibit 99.61 NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina Effective Date: December 31, 2025 Report Date: March 27, 2026 Report Prepared by: OCEANAGOLD Suite 1020, 400 Burrard Street Vancouver, BC V6C 3A6 Canada Signed by Qualified Persons: David Carr, Beng Metallurgical (Hons), MAusIMM (CP), (OceanaGold Head of Metallurgy) Gregory Hollett, BEng (Mining Engineering),

Consent of Independent Auditor

Exhibit 99.65 Consent of Independent Auditor We hereby consent to the incorporation by reference in this Registration Statement on Form 40-F of OceanaGold Corporation (the “Company”) of our report dated February 19, 2025 (except as to Note 11 which is as of February 18, 2026) relating to the consolidated financial statements as at and for the year ended December 31, 2024 which appears in Exhibit 9

CONSENT

Exhibit 99.67 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Report

OceanaGold Reports Fourth Quarter and Full Year 2024 Operating and Financial Results (All financial figures in United States dollars unless otherwise stated)

Exhibit 99.34 February 19, 2025 News Release OceanaGold Reports Fourth Quarter and Full Year 2024 Operating and Financial Results (All financial figures in United States dollars unless otherwise stated) •Met 2024 updated production guidance and achieved record annual production at Haile •Record annual Net Profit of $192 million and Free Cash Flow of $245 million •Doubling of annual dividend and in

OceanaGold Appoints Stefanie Loader to the Board of Directors

Exhibit 99.35 February 20, 2025 News Release OceanaGold Appoints Stefanie Loader to the Board of Directors (VANCOUVER) OceanaGold Corporation (TSX:OGC, OTCQX:OCANF) (“OceanaGold” or the “Company”) appoints Ms Stefanie Loader as Non-Executive Director to the Board of Directors (the “Board”), effective immediately. Paul Benson, Non-Executive Chairman of the Board, said "On behalf of the Board, I am

OceanaGold Announces Effective Date of Share Consolidation in Connection with Proposed U.S. Listing

Exhibit 99.42 June 19, 2025 News Release OceanaGold Announces Effective Date of Share Consolidation in Connection with Proposed U.S. Listing (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC, OTCQX: OCANF) (“OceanaGold” or the “Company”) announces the consolidation of its common shares on the basis of three (3) pre-consolidation common shares for one (1) post-consolidation common share (the “Consol

OceanaGold Provides Notice of Second Quarter 2025 Results and Conference Call

Exhibit 99.44 July 8, 2025 News Release OceanaGold Provides Notice of Second Quarter 2025 Results and Conference Call (VANCOUVER, BC) OceanaGold Corporation (TSX: OGC) (OTCQX: OCAND) (“OceanaGold” or the “Company”) will release its operational and financial results for the second quarter of 2025 after market close on Wednesday, August 6, 2025. The results will be made available on the Company’s we

FORM 13-501F1 CLASS 1 REPORTING ISSUERS AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION

Exhibit 99.56 Note: [01 Mar 2017] – The following is a consolidation of 13-501F1. It incorporates amendments to this document that came into effect on March 1, 2017. This consolidation is provided for your convenience and should not be relied on as authoritative. FORM 13-501F1 CLASS 1 REPORTING ISSUERS AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION I, VAN NIEKERK, Mari

FORM 13-502F1 CLASS 1 AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION

Exhibit 99.57 FORM 13-502F1 CLASS 1 AND CLASS 3B REPORTING ISSUERS – PARTICIPATION FEE MANAGEMENT CERTIFICATION I, VAN NIEKERK, Marius , an officer of the reporting issuer noted below have examined this Form 13-502F1 (the Form) being submitted hereunder to the Ontario Securities Commission and certify that to my knowledge, having exercised reasonable diligence, the information provided in the Form

CONSENT

Exhibit 99.80 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). Additionally, the undersigned is an author of the Technical Reports

CONSENT

Exhibit 99.81 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned has reviewed and approved certain technical and scientific information (the “Reviewed Information”) contained in, referenced in, or incorporated by reference into the Form 40-F (as defined below). The undersigned understands that the Company wishes to make referen

CONSENT

Exhibit 99.85 CONSENT To: OceanaGold Corporation (the “Company”) Re: Registration Statement on Form 40-F of the Company The undersigned is an author of each of the reports titled “NI 43-101 Technical Report Haile Gold Mine Lancaster County, South Carolina” with a report date of March 28, 2024, and with an effective date of December 31, 2023 and “NI 43-101 Technical Report – Haile Gold Mine, Lancas

OGDCF / Oceanagold Corporation / VAN ECK ASSOCIATES CORP Passive Investment

SC 13G/A 1 newgold13ga.htm SC 13G/A 1 schedule13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.5)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2022 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.4)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) (CUSIP Number) December 31

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.4)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2020 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

GSV / Gold Standard Ventures Corp. / OceanaGold Corp - SCHEDULE 13 G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.

Relevant Subsidiary Description

Exhibit 99.2 Relevant Subsidiary 1015776 BC Ltd. is a wholly-owned subsidiary of OceanaGold Corporation.

OGDCF / Oceanagold Corporation / VAN ECK ASSOCIATES CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.3)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2019 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

OGDCF / Oceanagold Corporation / VAN ECK ASSOCIATES CORP Passive Investment

SC 13G/A 1 schedule13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.2)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2018 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check the appropriate box to des

GSV / Gold Standard Ventures Corp. / OceanaGold Corp Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.

OGDCF / Oceanagold Corporation / VAN ECK ASSOCIATES CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.1)* OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2017 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to

OGDCF / Oceanagold Corporation / VAN ECK ASSOCIATES CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 OceanaGold Corp. (Name of Issuer) COMMON SHARES (Title of Class of Securities) 675222103 (CUSIP Number) December 31, 2016 - Year End Filing (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedu

GSV / Gold Standard Ventures Corp. / OceanaGold Corp Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2 UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.

GSV / Gold Standard Ventures Corp. / OceanaGold Corp Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 19341 (AMENDMENT NO.

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15F CERTIFICATION OF A FOREIGN PRIVATE ISSUER’S TERMINATION OF REGISTRATION OF A CLASS OF SECURITIES UNDER SECTION 12(g) OF THE SECURITIES ACT OF 1934 OR ITS TERMINATION OF THE DUTY TO FILE REPORTS UNDER SECTION 13(a) OR SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 000-55109 OceanaGold Corp

OCEANAGOLD AND PACIFIC RIM MINING COMPLETE PLAN OF ARRANGEMENT

EXHIBIT 99.1 November 27, 2013 OCEANAGOLD AND PACIFIC RIM MINING COMPLETE PLAN OF ARRANGEMENT (MELBOURNE) OceanaGold Corporation (“OceanaGold”) (ASX: OGC, TSX: OGC, NZX: OGC) and (VANCOUVER) Pacific Rim Mining Corp. (“Pacific Rim”) (TSX: PMU, OTCQX: PFRMF) are pleased to announce the successful completion of the plan of arrangement (the “Arrangement”) originally announced on October 8, 2013. The A

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November, 2013 Commission File Number: OCEANAGOLD CORPORATION (Translation of registrant’s name into English) Level 5 250 Collins Street Melbourne Victoria 3000 Australia (Address of principal

OceanaGold Corp

SC 13G 1 oceana-pacificrim13g101012.htm SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2 UNDER THE SECURITIES EXCHANGE ACT OF 1934 Pacific Rim Mining Corp. (Name of Issuer) Common Shares (Title of Class of Securities) 694915208 (CUSIP Number) October 2, 2012 (Date of Event Which Requires Filing of This Statement) Check the