Cotton County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 6,193. Its county seat is Walters. When Oklahoma achieved statehood in 1907, the area which is now Cotton County fell within the boundaries of Comanche County. It was split off in 1912, becoming the last county created in Oklahoma; it was named for the county's primary crop.Cotton County is included in the Lawton, OK Metropolitan Statistical Area.