Johnston is a city in Polk County, Iowa, United States.

Also located here are the Camp Dodge Military Reservation as well as the Paul J. and Ida Trier House, a private residence designed by architect Frank Lloyd Wright, and the Des Moines Weather Forecast Office of the National Weather Service.

[6] Passenger service along the railroad ended in 1949, and the track has subsequently been removed within city limits.

Incorporation papers were signed by the Clerk of the District Court on December 11, 1969.

At the time, the Johnston Station area did not become part of the incorporated city because of a state law that prevented a town within three miles (5 km) of another city from incorporating.

The city is bisected by Beaver Creek, which flows southerly through the city until it nearly reaches Interstate 80, at which point the course turn easterly and flows to the Des Moines River.

As of the census of 2020,[10] there were 24,064 people, 9,194 households, and 6,328 families residing in the city.

At the 2010 census there were 17,278 people, 6,369 households, and 4,720 families living in the city.

At the 2000 census there were 8,649 people, 3,216 households, and 2,318 families living in the city.

Corteva Agriscience and John Deere Financial are based in Johnston.

[13] The Johnston Community School District serves the city.

Routes 5 and 93 provide bus service connecting the city to the region.