The Pilchuck River is a river in Snohomish County in the U.S. state of Washington. It is a tributary of the Snohomish River. The name is derived from the Chinook Jargon pilpil and chuck, or "red water". The Lushootseed name means "flowing red," kʷiƛ̕ being an archaic term for "red" in Northern Lushootseed.