• Produced 138,800 ounces of gold, on track to deliver on full year guidance.
• Strong Free Cash Flow^† of $130 million, with cash of $655 million and no debt at quarter end.
• Advanced growth projects and returned $78 million to shareholders viabuybacks and dividends.

OceanaGold Corporation (TSX: OGC) (NYSE: OGC) reported its operational and financial results for the three and six months ended June 30, 2026. The consolidated financial statements and Management’s Discussion and Analysis are available at www.oceanagold.com.

Second Quarter Highlights

• On track to achieve full year production, cost and capital guidance, with production expected to increase and costs to decrease in the second half of 2026.
• Safely and responsibly produced 138,800 ounces of gold and 2,700 tonnes of copper, an increase in gold production of 7% from the prior quarter.
• All-In Sustaining Cost^† of $2,151 per ounce in the quarter, expected to decrease in the second half of 2026 with higher gold production and lower sustaining capital.
• Revenue of $647 million at an average realized gold price of $4,433 per ounce, reflecting gold sales weighted towards the end of the quarter as gold production increased at Haile.
• Net profit¹ of $222 million, EPS of $0.99 and record adjusted EBITDA Margin^† of 61%.
• Generated strong quarterly Operating Cash Flow of $314 million.
• Free Cash Flow^† of $130 million, and $385 million year to date.
• Cash balance increased by 6% to $655 million with no debt and revolving credit facility undrawn.
• Returned $78 million to shareholders in the quarter, via dividends and share buybacks.
• Completed $58 million in share buybacks during the quarter and $134 million year to date, with up to $350 million approved for 2026.
• Listed on the New York Stock Exchange (“NYSE”) on April 7, 2026, with trading volumes increasing.
• Reported additional high-grade drill results at Haile, highlighting the ongoing success of drilling to support resource growth and conversion, and continuing to demonstrate upside potential.
• Development of the decline towards Wharekirauponga commenced in May 2026, progressing to plan.
• Macraes produced its 6 millionth ounce of gold in July 2026, since beginning production in 1990.

Gerard Bond, President and CEO of OceanaGold, said “We are pleased to deliver another quarter of solid gold production, generating strong free cash flow which allows us to invest in our attractive organic growth projects, strengthen our balance sheet and still return meaningful capital to shareholders. During the quarter we commenced development of the decline towards the high-grade Wharekirauponga orebody, a significant milestone in advancing the Waihi North Project, and are progressing to plan. At Haile, we continued to progress the Palomino decline and released additional high-grade drill results that further demonstrate our ability to add value through the drill bit. With increased gold production expected in the second half of the year we remain focused on delivering on our guidance, reducing our unit costs, generating further free cash flow and continuing to create value for our shareholders.”

Results Overview

Outlook

The Company’s 2026 production, cost and capital Guidance is outlined in the table below and remains unchanged.

Production is expected to increase in the second half of the year, with consolidated third quarter production expected to be similar to the second quarter, and the fourth quarter being the strongest of the year.

At Haile, gold production is expected to increase in the third quarter, then again in the fourth quarter driven by higher grades mined in the Ledbetter Phase 3 open pit and the Horseshoe Underground. Macraes production is expected to be lower in the third and fourth quarters as per plan, while production at Waihi is expected to remain relatively consistent through the remainder of the year. At Didipio, production is expected to be higher in the third and fourth quarters driven by an increase in underground mining rates.

Consolidated AISC^† is anticipated to be near the upper end of the Company’s 2026 Guidance range, reflecting labour cost inflation, continued investment in maintenance and reliability improvements, unhedged energy costs and lower silver by-product credits. Consolidated AISC^† is expected to be lower in the third quarter and again in the fourth quarter, underpinned by lower sustaining capital and higher production at Haile. AISC^† at each of Haile, Didipio and Waihi is expected to reduce in the second half of the year. AISC^† at Macraes is expected to increase in the second half, with its full-year AISC^† expected to be within its Guidance range.

Total capital investment guidance remains unchanged, with spending on growth capital expected to increase in the second half of the year, primarily driven by the continued investment in the Waihi North and Palomino Underground Projects and waste stripping activities at Haile, while sustaining capital across the portfolio is expected to decrease in the second half of the year.

2026 Full-Year Guidance

Waihi North Project

OceanaGold is permitted to develop and operate the Waihi North Project, which includes the high-grade Wharekirauponga Underground mine. Construction and underground tunnelling activity to the underground mine continues to ramp up with overall project development progressing on schedule for first ore in 2032.

Following completion of the portal, decline development commenced in May 2026 and is progressing in line with plan, nearing 200 metres to date. The next key milestone involves the addition of a second jumbo to begin the twin incline towards the Wharekirauponga orebody.

Execution of bulk earthworks accelerated at the Willows Portal site in the second quarter and earthwork activities related to drainage, dams, roads, magazine and the surface facilities area remain on track for completion by year-end. Construction of the services trench connecting the existing Waihi operations with the Willows surface facilities, providing power, water and communications infrastructure, was completed in July. Construction of the water treatment plant remains ongoing, with commissioning expected by the end of the third quarter. Early works activities on TSF 3 are expected to commence in the fourth quarter.

Dividend

OceanaGold has declared a $0.09 per share dividend payable in September 2026. Shareholders of record at the close of business in each jurisdiction on August 19, 2026 (the “Record Date”) will be entitled to receive payment of the dividend on September 18, 2026. The dividend payment applies to holders of record of the Company’s common shares traded on the TSX and the NYSE.

Dividends are payable in United States dollars. Shareholders in other jurisdictions can elect to participate in Computershare’s international payments service if they want to receive dividends in an alternative currency. This dividend qualifies as an ‘eligible dividend’ for Canadian income tax purposes.

Share Buyback

In the first half of 2026, the Company completed $134 million of share repurchases. In February, the Company announced approval to apply up to $350 million towards share buybacks in 2026. The Company recently renewed its Normal Course Issuer Bid for another 12 months.

About OceanaGold

OceanaGold is a global intermediate gold and copper producer committed to safely and responsibly maximizing the generation of Free Cash Flow from our operations and delivering strong returns for our shareholders. We have a portfolio of four operating mines: the wholly-owned Haile Gold Mine in the United States of America; the wholly-owned Macraes and Waihi operations in New Zealand; and the 80%-owned Didipio Mine in the Philippines.