OceanaGold Receives SEIS Record of Decision and Mine Operating Permit for Haile Gold Mine Expansion

First ore from the Haile underground on-track for the fourth quarter of 2023

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VANCOUVER, Dec. 19, 2022 - OceanaGold Corp. (TSX: OGC) ("OceanaGold" or the "Company") is pleased to announce that the United States Army Corps of Engineers ("ACOE") has issued the Supplementary Environmental Impact Statement Record of Decision ("SEIS ROD") and granted a permit under Section 404 of the Clean Water Act ("404 Permit") for the expansion of the Haile Gold Mine ("Haile") located in Kershaw, South Carolina. The receipt of the SEIS ROD and 404 Permit by the ACOE completes the federal permitting process for the Haile expansion.

In addition, the South Carolina Department of Health and Environmental Control ("DHEC") issued the Mine Operating Permit ("MOP") on December 14, 2022, which, following a statutory 15-day period, will become final and will complete the state permitting process for the Haile expansion.

OceanaGold President and CEO, Gerard Bond, said "The receipt of the Haile SEIS ROD and the MOP represents a significant milestone for OceanaGold, putting the Company on a clear path to deliver increased gold production and lower unit costs at this cornerstone asset. We are thrilled to be progressing the next stage of Haile's growth as we expand our operations underground and, with exploration success, pursue further opportunities to profitably extend the mine life."

The receipt of the SEIS ROD, 404 Permit and the MOP allows for development and operation of the underground mine and an expansion of the operating footprint to allow for additional waste containment facilities and expanded tailings storage capacity.

With the early works program approved in the third quarter, underground development of the main production decline and exhaust ventilation portals is safely progressing in-line with plan. First ore from the Haile underground remains on-track for delivery in the fourth quarter of 2023.

About OceanaGold

OceanaGold is a multinational gold producer committed to the highest standards of technical, environmental and social performance. We are committed to excellence in our industry by delivering sustainable environmental and social outcomes for our communities, and strong returns for our shareholders. Our global exploration, development, and operating experience has created a strong pipeline of organic growth opportunities and a portfolio of established operating assets including the Haile Gold Mine in the United States of America, Didipio Mine in the Philippines, and the Macraes and Waihi operations in New Zealand.

www.oceanagold.com | Twitter: @OceanaGold

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SOURCE OceanaGold Corp.