Haro Strait, often referred to as the Haro Straits because it is really a series of straits, is one of the main channels connecting the Strait of Georgia to the Strait of Juan de Fuca, separating Vancouver Island and the Gulf Islands in British Columbia, Canada from the San Juan Islands of Washington state in the United States.

Haro Strait is a critical part of the route of the international boundary between Canada and the United States from the western terminus of the 49th parallel segment of that boundary, and was chosen by the arbitrator in the San Juan Islands dispute (Pig War) over the other main candidate, Rosario Strait, which lies on the east side of the San Juans.