OceanaGold Corporation — Proxy Solicitation & Information Statement 2023

May 9, 2023

Have questions about this notice? Call the Toll Free Number below or scan the QR code to find out more.

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Notice of Availability of Proxy Materials and Notice of Meeting for OCEANAGOLD CORPORATION Annual General and Special Meeting

Meeting Date and Location:

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When: June 15, 2023 Where: Online at https://meetnow.global/M6WLZJP 9:00 am (Eastern Time)

You are receiving this notice to advise of the time, date and location of the above noted shareholders’ meeting and that the proxy materials for the above noted shareholders’ meeting are available on the Internet. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We remind you to access and review all of the important information contained in the information circular and other proxy materials before voting.

If you are a registered shareholder or duly appointed and registered proxyholder and wish to attend, vote and/or participate at the above noted meeting, on the day of the meeting log into the meeting from your computer or mobile device by entering above noted URL in the browser and following the prompts to log in, vote and participate at the meeting when prompted.

The information circular and other relevant materials are available at:

http://www.envisionreports.com/OceanaGold2023AGSM

OR

www.sedar.com

How to Obtain Paper Copies of the Proxy Materials

Securityholders may request to receive paper copies of the current meeting materials by mail at no cost. Requests for paper copies may be made using your Control Number as it appears on your enclosed Voting Instruction Form or Proxy. To ensure you receive the materials in advance of the voting deadline and meeting date, all requests must be received no later than June 5, 2023 at 5:00 pm. If you do request the current materials, please note that another Voting Instruction Form/Proxy will not be sent; please retain your current one for voting purposes.

For Holders with a 15 digit Control Number:

Request materials by calling Toll Free, within North America - 1-866-962-0498 or direct, from Outside of North America - +1-514-982-8716 and entering your control number as indicated on your Voting Instruction Form or Proxy.

To obtain paper copies of the materials after the meeting date, please contact 1-844-916-0609 (Toll Free) or +1-303-562-9305 (Direct).

For Holders with a 16 digit Control Number:

Request materials by calling Toll Free, within North America - 1-877-907-7643 or direct, from Outside of North America - +1-303-562-9305 and entering your control number as indicated on your Voting Instruction Form.

To obtain paper copies of the materials after the meeting date, please contact 1-844-916-0609 (Toll Free) or +1-303-562-9305 (Direct).

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Securityholder Meeting Notice

The resolutions to be voted on at the meeting are listed below along with the Sections within the Information Circular where disclosure regarding the matter can be found.

1. Election of Directors - Election of Directors

2. Appointment of Auditors - Appointment of Auditor

3. Advisory Vote on Executive Compensation - Advisory Vote on Executive Compensation

Voting

PLEASE NOTE - YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your securities you must vote using the methods reflected on your enclosed Voting Instruction Form or Proxy

PLEASE VIEW THE INFORMATION CIRCULAR PRIOR TO VOTING

Annual Financial statement delivery

• Only Registered and Beneficial holders who have opted to receive one

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