Piers Island is a small island in , British Columbia, Canada. The channel joins Saanich Inlet on the west with to Haro Strait on the east, which is the section of the Canada–US border separating the Gulf Islands in British Columbia, of which Piers is a part, from the San Juan Islands of Washington state. Haro Strait is part of the Inside Passage from Washington to Alaska through which ships can find waters relatively sheltered from Pacific Ocean waves and storms for most of its length. Piers Island is separated from the somewhat larger Portland Island by to the northeast.