Neosho (; originally Siouan pronunciation: [niˈoʒo] or Siouan pronunciation: [niˈoʒu]) 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 a 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 name "Neosho" is generally accepted to be of Native American (most likely Osage) derivation, meaning "clear, cold water", referring to local freshwater springs. The springs attracted varying cultures of Native American inhabitants for thousands of years. It was also ideal for the later white settlers, who founded the city in 1833. It was incorporated as a municipal government in 1878. Nicknamed "City of Springs", Neosho has long served as an agricultural center and, since 1888, is home of the Neosho National Fish Hatchery, the oldest in the National Fish Hatchery System. It is known locally as the "Gateway to the Ozarks", and since 1957 as "the Flower Box City".
Starting in the late 1820s, settlers of English, Scottish, German, Welsh, and Scots-Irish ancestry began moving into the area.