Cortes Island is an island in the Discovery Islands archipelago on the coast of British Columbia, Canada. The island is 25 km long, 13 km wide, and 130 km2 in area. It has a population of 1,035 permanent residents. Cortes Island lies within Electoral Area B of the Strathcona Regional District, which provides water and sewage systems, fire protection, land use planning, parks, recreation, and emergency response.