Alsea /ˈælsiː/ or Alsean (also Yakonan) was two closely related speech varieties spoken along the central Oregon coast until the early 1950s.

[2] Alsea is usually considered to belong to the Penutian phylum, and may form part of a Coast Oregon Penutian subgroup together with Siuslaw and the Coosan languages.

[3] Numerous lexical resemblances between Alsea and the Northern Wintuan languages, however, are more likely the result of borrowing about 1,500 years ago when the (Northern) Wintuan speech community appears to have been located in Oregon.

The name Alsea derives from the Coosan name for them, alsí or alsí·, and the Marys River Kalapuyan name for them, alsí·ya.

Alsea was last recorded in 1942 from the last speaker, John Albert, by J. P. Harrington.