The Squaxin Island Tribe (also Squaxin, Squaxon) is a Native American tribal government in western Washington state in the United States. The Squaxin Island Tribe is made up of several Lushootseed clans: the Noo-Seh-Chatl, Steh-Chass, Squi-Aitl, T'Peeksin, Sa-Heh-Wa-Mish, Squawksin, and S'Hotle-Ma-Mish. They live along several inlets of southern Puget Sound.
The Squaxin Island people speak the Lushootseed language. They moved onto their reservation in modern-day Mason County, Washington, in 1855. The Squaxin Island Tribe was one of the first Native American tribes in the U.S. to enter into the Self Governance Demonstration Project with the federal government.
The Squaxin Island Indian Reservation is in southeastern Mason County, Washington. Most of the main reservation is composed of Squaxin Island, but there is also a small part of 26.13 acres (105,700 m2) at Kamilche, in addition to two parcels of off-reservation trust land near Kamilche, as well as a plot of 6.03 acres (24,400 m2) across Pickering Passage from Squaxin Island and a plot of 35.93 acres (145,400 m2) on Harstine Island, across Peale Passage. The total land area including off-reservation trust lands is 6.942 km² (2.68 sq mi, or 1,715.46 acres). Of the total resident population of 405 persons (2000 census), 383 lived in off-reservation trust land to the southeast of Kamilche, and 22 lived on Harstine Island, while the bulk of the reservation's territory, Squaxin Island, was unpopulated.