The William S. Clark House, in Eureka, Humboldt County, northern California was built in 1888 by master carpenter Fred B. Butterfield. Its design includes elements of both Eastlake and Queen Anne Styles of Victorian architecture. It was built for William S. Clark, a businessman, real estated developer, and mayor of Eureka. It was listed on the National Register of Historic Places in 1988. The builder, Fred Butterfield, co-built (along with Walter Butterfield) the NRHP-listed Thomas F. Ricks House at 730 H St. in Eureka.