Downey is a city in the Marsh Valley in southern Bannock County, Idaho, United States. It is part of the Pocatello Metropolitan Statistical Area. The population was 571 at the 2020 census. The community was reportedly named after one Mr. Downey, a director of the Union Pacific Railroad. However, researchers have been unable verify existence of said Mr. Downey. Notwithstanding, some have asserted he was a track worker, not a director.