Alexander Duncan (24 February 1884 – 21 January 1959) was a British long-distance runner.

He then picked up more victories in Barrow, Dalton-in-Furness, Darlington, Jendal, Glasgow, and Leeds.

[8] Duncan competed in the men's marathon at the 1908 Summer Olympics[9] but did not finish along with seven of his teammates.

[3] Duncan was scheduled to race in the US and Canada in 1909 as part of a tour with Fred Appleby.

[2] Duncan was also said to be skilled at gardening and produced "admired" floral displays".