West Des Moines is a city in Iowa, United States. A majority of the city is located in Polk County, a minority of the city is located in Dallas County, and small portions extend into Warren and Madison Counties.

Polk County is located in the U.S. state of Iowa. As of the 2020 census, the population was 492,401. It is Iowa's most populous county, and home to over 15% of the state's residents. The county seat is Des Moines, which is also the capital city of Iowa. Polk County is included in the Des Moines–West Des Moines, IA Metropolitan Statistical Area.