Filer (FĪ-ler) is a city in Twin Falls County, Idaho, United States. The population was 2,508 at the 2010 census. Filer is located just west of the intersection of U.S. Routes 93 and 30.
It was named after Walter G. Filer, who served as general manager of the Twin Falls Water and Land Company. The city was established in 1906 as the terminus of the Oregon Short Line branch of Twin Falls. Walter Filer was a mining engineer and surveyor from Sharon, Pennsylvania, who supervised the construction of the Milner diversion dam on the Snake River. Since 1916, the City of Filer has been the home of the Twin Falls County Fair and Rodeo (Magic Valley Stampede).