Osisko Appoints Richard Ross to Board of Directors

MONTREAL, QUEBEC--(Marketwire - Sept. 15, 2011) - Osisko Mining Corporation ("Company")(TSX:OSK)(FRANKFURT:EWX) Deutsche Boerse) is pleased to announce the appointment of Mr. Richard A. Ross, C.A. to the Board of Directors.

Mr. Ross has more than 30 years of progressive experience within the mining industry. Most recently he served as Chief Executive Officer of Inmet Mining Corporation (2000-2009), including five years as Chairman. Mr. Ross is currently a member of the Board of Directors of Cliffs Natural Resources, Chair of St.Joseph's Health Centre in Toronto, and Executive in Residence responsible for the development of the Global Mining Management MBA Program at York University's Schulich School of Business.

Victor H. Bradley, Chairman of the Board of Directors, commenting on Mr. Ross's appointment stated: "We are very pleased to have Mr. Ross join our Board. With his depth of experience we look forward to benefit from his knowledge of the global mining industry to assist Osisko in our pursuit of developing into a leading intermediate gold producer."

About Osisko Mining Corporation

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Quebec and is pursuing exploration on a number of properties, including the Hammond Reef Gold Project in Northern Ontario. Canadian Malartic's production is 100% unhedged.