Kelso is a village in Scott County, Missouri, United States. The population was 527 at the 2000 census. The Kelso ZIP code of 63758 appears to be for residents who wish to receive their mail at the Kelso post office; direct mail delivery in Kelso appears to use the Scott City ZIP code of 63780. The first post office was established in 1840; however, the name of the settlement was changed from Spring Hills to Kelso when the post office was reopened in 1858. The post office was closed in 1861, but it was reopened after the war in 1874 by a former Civil War bugler. A grocery store was located here as early as 1849, and a mill was located here as early as 1866.