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. As of the 2020 census, the city population was 68,723. West Des Moines is the second-most populous city in the Des Moines metropolitan area and the sixth-most populous city in Iowa. It is the largest city in Iowa that is not a county seat of any county that it resides in.