Filer (FĪ-ler) is a city in Twin Falls County, Idaho, United States.

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).

According to the United States Census Bureau, the city has a total area of 1.06 square miles (2.75 km2), all of it land.

27.7% of all households were made up of individuals, and 10.8% had someone living alone who was 65 years of age or older.

The Twin Falls County Fair is located in Filer, occurring in the first week of September.