Filer (FĪ-ler) is a city in Twin Falls County, Idaho, United States. The city population was 2,508 at the 2000 census, up from 1,620 in 2000. 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.