The club was founded in 1877,[2] as Thornhill Football Club (later 'Thornhill United'), before, in 1905, changing to Rotherham County.[3] It joined the Midland League in 1903,[3] and stayed in that competition until it was abandoned for World War I. They won the Midland League title for four consecutive seasons, from 1911–12 to 1914–15 inclusive.[3]
After the War, they were elected to the Football League when the league expanded from 40 clubs to 44 in 1919. In 1925 they merged with local rivals Rotherham Town to form Rotherham United[3] who are still members of the Football League.