Mansfield is a town in Douglas County, Washington, United States. It is part of the Wenatchee–East Wenatchee Metropolitan Statistical Area. The population was 326 at the 2020 census. R.E. Darling named Mansfield in 1905 after his hometown of Mansfield, Ohio. Mansfield's land was purchased and first developed in 1909 by the Great Northern Railway…Mansfield is a town in Douglas County, Washington, United States. It is part of the Wenatchee–East Wenatchee Metropolitan Statistical Area. The population was 326 at the 2020 census. R.E. Darling named Mansfield in 1905 after his hometown of Mansfield, Ohio. Mansfield's land was purchased and first developed in 1909 by the Great Northern Railway. Mansfield was officially incorporated on February 23, 1911.