Deep Bay is an unincorporated area on the east coast of Vancouver Island, in British Columbia, Canada across Baynes Sound from Denman Island which has a government marina in a naturally protected harbour. It is situated on Highway 19A north of Qualicum Beach between Fanny Bay and Bowser.
The June 23, 1946 Vancouver Island earthquake shocked the Strait of Georgia region, causing the bottom of Deep Bay to sink between and .
Deep Bay is the home of the Deep Bay Marine Field Station.
The Island Rail Corridor passes through the area.