Robert Hamilton Turnbull (22 June 1894 – 1946) was a Scottish footballer. Turnbull was originally a soldier, serving in the Royal Corps of Signals, and joined Arsenal in 1921 as an amateur. He was originally a left back and made his debut on 27 December 1921 against Cardiff City at Ninian Park; Arsenal lost 3–4 in a tightly fought game. Turnbull only played occasionally at this stage, making only five appearances in the 1921–22 season.