narrow passage, 11–17 miles (18–27 km) in width, of the eastern North Pacific Ocean, between the Olympic Peninsula of Washington state, U.S., and Vancouver Island, British Columbia, Can. Part of the United States–Canadian international boundary lies in mid-channel.

From Cape Flattery and the open Pacific, the strait stretches 80–100 miles (130–160 km) east to join with Haro Strait and touches Whidbey Island, which blocks the entrance to Puget Sound (south). Mid-channel depths decrease from 900 feet (275 m) at its Pacific entrance to 300 feet (90 m) in the east. Tidal movements are complicated by northward-moving flood tides from the Pacific coast of Washington entering the strait during part of the time when a conflicting westward-flowing ebb tide is going out. Tidal rips are common off points and over shallows. Strong west or southwest winds are also common. The strait, which is named for a Greek who sailed in the service of Spain and may have visited the passage in 1592, is used by ships bound for Vancouver and Seattle. Settlements along its banks include Victoria, B.C. (northeast), and Port Angeles, Wash. (southeast).