Fort Stevens was an American military installation that guarded the mouth of the Columbia River in the state of Oregon. Built near the end of the American Civil War, it was named for Civil War general and former Washington Territory governor, Isaac I. Stevens. The fort was an active military reservation from 1863–1947. It is now listed on the National Register of Historic Places.

Isaac Ingalls Stevens was an American military officer and politician who served as governor of the Territory of Washington from 1853 to 1857, and later as its delegate to the United States House of Representatives. During the American Civil War, he held several commands in the Union Army. He was killed at the Battle of Chantilly, while at the head of his men and carrying the fallen colors of one of his regiments against Confederate positions. According to one account, at the hour of his death Stevens was being considered by President Abraham Lincoln for appointment to command the Army of Virginia. He was posthumously advanced to the rank of Major General. Several schools, towns, counties, and lakes are named in his honor.