The Ontario Alliance of Climbers (OAC) is a volunteer, not-for-profit group that works with the climbing community, land owners, conservation authorities and property managers to keep climbing and bouldering areas open in an environmentally responsible manner.

In March 2009, the OAC, then known as the Ontario Access Coalition, incorporated as a not-for-profit corporation. The primary purpose of this restructuring was to become a more accessible organization whose purpose is to work with climbers as well as land managers regarding access issues. The OAC would like to extend a special thanks to the MEC for its grant, which funded the OAC’s incorporation.  The OAC was renamed as the Ontario Alliance of Climbers in December 2018.