Douglas "Dally" Duncan (14 October 1909 – 2 January 1990) was a Scottish football player and manager. A left-winger, Duncan joined Hull City from Aberdeen Richmond in 1928 and spent his entire professional career in English football. He joined Derby County for £2,000 in 1932 and remained contracted to the club until 1946. During this period he earned 14 caps for the Scottish national team, scoring 7 goals between 1932 and 1937. He also received an FA Cup winners medal with Derby in 1946. Duncan ran a guest house in Brighton after his football retirement. He died in 1990, aged 80.