Exploration Activity At the Haile Gold Mine

MELBOURNE - OceanaGold Corporation reported an update on exploration activity at the Company's Haile gold mine in South Carolina. Mick Wilkes, President and CEO said, "I am very pleased to announce the results of brownfields drilling at Haile over the past nine months that are expected to add more low-cost ounces to our reserves.  These results demonstrate the potential for additional mineralization close to surface between current pit designs and at depth. Comprehensive geological reassessment from mapping and core logging has identified important structural controls that are being applied to our 3D models which will play a critical role in ongoing and future target generation.  Haile's exploration team is also driving innovative modeling for emerging geophysical targets that will be pursued in 2019."

"Since acquiring the Haile Gold Mine in late 2015, we have delivered a 70% increase in reserves and, through our exploration program, we continue to learn more about the genesis of the mineralization. Through this greater understanding, we are improving our mine planning and design which fits well with our continued focus on improving productivities and reducing costs. In addition to exploration, the Company continues to advance the expansion of the process plant with the pebble crusher now fully constructed and commissioned. The Tower and Isa Mills, critical processing equipment for the expansion and recovery enhancement, are scheduled for completion in the first quarter of 2019, said Wilkes.”

Since the last exploration update on November 8, 2017, the Company has drilled 100 drill holes for a combined 26,149 meters at Haile using four surface diamond drills. Resource infill and extension drilling has targeted low-cost reserve growth areas in and around the Ledbetter, Mustang, Mill Zone, Snake, Red Hill, and Haile deposits.

Favorable extension drill results are expected to add ore-grade mineralization between pit designs at low strip ratios. Pit designs will likely be merged between the Mill Zone/Mustang and Ledbetter/Snake pit designs. Drilling below the northwest wall of the Mill Zone Phase 1 pit returned positive results and a Phase 2 layback design is in progress. Infill and delineation drilling continue to support our models and robust mineralization, notably in the upper Ledbetter area. Shallow, medium-grade drill intercepts have been confirmed in diamond holes at Red Hill which is scheduled for mining in 2019. An 18-hole diamond drill program was conducted outside the reserve pit design at the Snake West extension and returned positive results. Further drilling is planned in the second half of 2018 at Ledbetter, Mill Zone and Snake.

Assays received from delineation drilling continue to validate high-grade, continuous mineralization at the Horseshoe underground deposit.