Downey is a city in the Marsh Valley in southern Bannock County, Idaho, United States.

The community was reportedly named after one Mr. Downey, a director of the Union Pacific Railroad.

According to the United States Census Bureau, the city has a total area of 0.99 square miles (2.56 km2), all of it land.

30.6% of all households were made up of individuals, and 19.6% had someone living alone who was 65 years of age or older.

There were 264 housing units at an average density of 268.2 per square mile (103.6/km2).

27.0% of all households were made up of individuals, and 18.9% had someone living alone who was 65 years of age or older.

Downey is part of the Marsh Valley School Joint District #21 and is served by three schools: Downey is served by one U.S. Highway and one state highway: