The Snoqualmie River is a 45-mile (72 km) long river in King County and Snohomish County in the U.S. state of Washington. The river's three main tributaries are the North, Middle, and South Forks, which drain the west side of the Cascade Mountains near the town of North Bend and join near the town of Snoqualmie just above the Snoqualmie Falls. After the falls the river flows north through rich farmland and the towns of Fall City, Carnation, and Duvall before meeting the Skykomish River to form the Snohomish River near Monroe. The Snohomish River empties into Puget Sound at Everett. Other tributaries of the Snoqualmie River include the Taylor River and the Pratt River, both of which enter the Middle Fork, the Tolt River, which joins at Carnation, and the Raging River at Fall City.

King County is located in the U.S. state of Washington. The population was 2,269,675 in the 2020 census, making it the most populous county in Washington, and the 12th-most populous in the United States. The county seat is Seattle, also the state's most populous city.