Kimmswick is a city in Jefferson County, Missouri, United States. The population was 157 at the 2010 census. Kimmswick is next to the Mis…Kimmswick is a city in Jefferson County, Missouri, United States. The population was 157 at the 2010 census. Kimmswick is next to the Mississippi River. According to the United States Census Bureau, the city has a total area of 0.23 square miles, all land.