Startup is a census-designated place (CDP) in Snohomish County, Washington, United States. The population was 676 at the 2010 census.
Startup was homesteaded by F.M. Sparling in the 1880s. In 1890 William Wait laid out a townsite which he called Wallace, but this caused confusion with mail being missent to Wallace, Idaho, and in 1901 the name was changed to Startup to honor George G. Startup, manager of the Wallace Lumber Company.The Startup post office was established in 1900.