Newton County is a county located in the southwest portion of the U.S. state of Missouri. As of the 2010 census, the population was 58,114. Its county seat is Neosho. The county was organized in 1838 and is named in honor of John Newton, a hero who fought in the Revolutionary War.Newton County is part of the Joplin, MO Metropolitan Statistical Area.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (0.3%) is water.Adjacent counties Jasper County (north) Lawrence County (northeast) Barry County (southeast) McDonald County (south) Ottawa County, Oklahoma (west) Cherokee County, Kansas (northwest)LakesTotal lake area: 2573acre Newtonia Lake Thurman LakeRivers & creeksTotal river area: 361acre; length: 70mi