GOLD  $US/OZ $ NYSE:OR  $ TSX:OR    $      

31

07-2017

Special Meeting of Shareholders – Transaction with Orion Mine Finance

The special meeting of shareholders of Osisko is scheduled to be held at 9:00 a.m. (Montréal time) on Monday, July 31, 2017 at the offices of Lavery, de Billy, L.L.P. located at 1 Place Ville Marie, Suite 4000, Montréal, Québec, Canada, H3B 4M4.

Your vote is important regardless of the number of shares you own. Osisko encourages shareholders to read the meeting materials in detail. An electronic copy of the Circular is available on Osisko’s website at www.osiskogr.com. It will also be available under Osisko’s issuer profiles on SEDAR at www.sedar.com and EDGAR at www.sec.gov.