neosho (; originally is the most populous city in newton county, missouri, united states, which it serves as the county seat. with a population of 11,835 as of the 2010 census, the city is part of the joplin, missouri metropolitan statistical area, a region with an estimated 176,849 (2011) residents. neosho lies on the western edge of the ozarks. the cost of living in neosho is low at about 9.9% less than the missouri average and 17.9% less than the national average.