Andrew Haydon (June 28, 1867 – November 10, 1932) was a Canadian lawyer and senator.

Born in Pakenham, Ontario, the son of James Haydon, a British immigrant,[2] and Eleanor Sadler,[1] he received a Master of Arts degree in 1893 and a Bachelor of Law degree in 1895 from Queen's University.

He graduated from Osgoode Hall Law School in 1897 and was soon after called to the Ontario Bar.

In 1924, he was appointed to the Senate of Canada representing the senatorial division of Ottawa, Ontario.

He was the author of Pioneer Sketches of The District of Bathurst (Lanark and Renfrew Counties, Ontario) (The Ryerson Press, 1925) and Mackenzie King and the Liberal Party (Allen, 1930).