OSISKO MINING CORPORATE UPDATE

(Toronto, September 16, 2020) Osisko Mining Inc. (OSK:TSX) (“Osisko” or the “Corporation”) is pleased to provide the following corporate update.

Mr. John Burzynski has been appointed as Chairman of the board of directors and remains in his role as Chief Executive Officer and as a director; Mr. Sean Roosen has stepped down from his role as non-executive Chairman of the board and remains in his role as a director; and Mr. Mathieu Savard has been promoted to President.

A graduate of the Université du Québec à Montréal with a bachelor’s degree in earth sciences with over 20 years’ experience in the mining industry, Mr. Savard served previously as Osisko’s Senior Vice-President Exploration.  Prior to joining Osisko Mining in 2016, Mathieu was a senior member of the Osisko Exploration James Bay, Virginia Gold and Virginia Gold Mines teams. Mathieu was a key member of the Virginia team which received the Association de l’Exploration Minière du Quebec (“AEMQ”) Prospector of the Year Award in 2004 and the PDAC’s prestigious Bill Dennis Award in 2006 for the discovery of the Eleonore gold deposit, and along with the Osisko Mining management and exploration team received the AEMQ 2017 Discovery of the Year Award, for the discovery of the Lynx deposit at Windfall.  Mathieu is a registered P.Geo.  as a member of the Ordre des Géologues du Québec and is Chairman of the board and a director of the AEMQ.

Chief Executive Officer and Chairman of the Corporation John Burzynski commented:  “I would like to thank Sean Roosen very much for his past tenure as Chairman, and for continuing in his role as a director.  I am very pleased to welcome Mathieu as the incoming President of Osisko Mining, and I look forward to him leading our team in the next stages of the work at Windfall, and to making additional discoveries in the coming years.  Our goal on the re-creation of Osisko Mining in 2015 was to discover and develop another world class gold mine in Québec.  We acquired a promising deposit, a district-scale land package, assembled one of the best exploration teams in the business, and commenced one of the world’s largest drill programs at Windfall.  Five years of persistence and hard work have paid off with the discovery of Lynx and the delineation of a world class deposit.

Osisko’s management and Board has had an unusual level of success in the Canadian mining business, leading to the last three world class gold discoveries in Québec (Windfall, Canadian Malartic, and Eleonore).  Our independent Lead Director was additionally responsible for leading the team that discovered the world class Fruta del Norte deposit in Ecuador. All this to say that at Osisko we have a strong and highly experienced Board and management team, one of the finest and most capable technical teams in the business, and one of the most proven track records of gold discovery and value creation for shareholders amongst any of our peers.  I have every confidence that Mathieu’s strong leadership skills will continue to take us to new heights.”

About Osisko Mining Inc.

Osisko is an exploration company focused on the acquisition, exploration, and development of precious metal resource properties in Québec.  Osisko holds a 100% interest in the high-grade Windfall gold deposit located between Val-d’Or and Chibougamau and holds a100% undivided interest in over 2,700 square kilometres in the surrounding Urban Barry and Quévillon area.

For further information please contact:   John Burzynski, Chief Executive Officer and Chairman    Telephone: (416) 363-8653