Buchan started his career in 1909 with Woolwich Arsenal (later renamed Arsenal F.C.). He is known for his career with Sunderland, where he became leading scorer for 7 of his 9 seasons with the club. He remains the club's all-time record League goalscorer. He was a winner of the First Division title in 1913, and reached the 1913 FA Cup Final with Sunderland.