is a city in Polk County, Iowa, United States. The population was 8,649 at the 2000 census; the United States Census Bureau estimated that 15,261 residents lived there in 2007. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area.
Johnston is the location of the headquarters of Pioneer Hi-Bred Seeds, Iowa Public Television, and The Gardeners of America/Men's Garden Clubs of America. The Camp Dodge Military Reservation is also located here.
Johnston was established in 1905 as a station on the interurban railway between Des Moines and Perry known as Johnston Station. It was named for the railway's freight supervisor, John F. Johnston.
Incorporation did not come until September 18, 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 neighboring cities of Des Moines and Urbandale were also interested in that land, but in April 1970, Johnston and Urbandale reached an agreement that allowed Johnston to annex the Johnston Station area.