channel linking the Atlantic and Pacific oceans, between the mainland tip of South America and Tierra del Fuego island. Lying entirely within Chilean territorial waters, except for its easternmost extremity touched by Argentina, it is 350 miles (560 km) long and 2–20 miles (3–32 km) wide. It extends westward from the Atlantic between Cape Vírgenes and Cape Espíritu Santo, proceeds southwestward, and curves to the northwest at Froward Cape on the southern tip of Brunswick Peninsula to reach the Pacific Ocean after passing Cape Pillar on Desolación Island. The strait's major port is Punta Arenas, on the Brunswick Peninsula; the port is a shipping point for Chilean mutton.

The first European to navigate the strait was Ferdinand Magellan (Magellan, Ferdinand) (Oct. 21–Nov. 28, 1520), a Portuguese sailing for Spain, whose expedition eventually completed the first circumnavigation of the world. Although the strait follows a somewhat tortuous course among numerous islands and channels and has a cold, foggy climate, it was an important sailing-ship route before the building of the Panama Canal (completed in 1914) shortened the Atlantic-Pacific passage by several thousand miles.