Clinton is a city in and the county seat of Clinton County, Iowa, United States. It borders the Mississippi River. The population was 24,469 a…Clinton is a city in and the county seat of Clinton County, Iowa, United States. It borders the Mississippi River. The population was 24,469 as of 2020. Clinton, along with DeWitt, was named in honor of the sixth governor of New York, DeWitt Clinton. Incorporated on January 26, 1857, Clinton is the principal city of the Clinton Micropolitan Statistical Area, which is coterminous with Clinton County.