Steilacoom is a town in Pierce County, Washington, United States. The population was 5,985 at the 2010 census.
The origin of the name "Steilacoom" is unclear. According to the Legacy Washington program, the town’s name is derived from an Indian word meaning “little pink flower.” Another version is that it was named by fur traders with the Hudson's Bay Company (HBC) and is an adaptation of Tail-a-Koom, the name of an Indian chief. The Town of Steilacoom says it was named after the Steilacoom tribe, especially their main village in the Tacoma area, located on Chambers Bay. Steilacoom's main source of early prosperity was the processing and export of lumber to San Francisco. When the United States Congress established the Washington Territory on March 2, 1853, Governor Isaac Stevens chose Steilacoom as the seat of Pierce County.