Steilacoom is a town in Pierce County, Washington, United States. The population was 6,727 at the 2020 census. Steilacoom incorporated in 1854 and became the first incorporated town in what is now the state of Washington. It has also become a bedroom community for service members stationed at Joint Base Lewis–McChord, aka McChord AFB and Fort Lewis. Based on per capita income, Steilacoom ranks 61st of 522 areas ranked in the state of Washington.