The Smith River (Tolowa: ) is a river flowing from the Klamath Mountains to the Pacific Ocean in Del Norte County in extreme northwestern California, on the West Coast of the United States. It is about 25.1 miles (40.4 km) long, all within Del Norte County, and it flows through the Rogue River - Siskiyou National Forest, Six Rivers National Forest, and Jedediah Smith Redwoods State Park.