John Farquharson McIntosh (1846-1918) was a Scottish engineer. He was Chief Mechanical Engineer of the Caledonian Railway from 1895 to 1914. He was succeeded by William Pickersgill.

The Caledonian Railway 721 Class was a class of 4-4-0 steam locomotives designed by John F. McIntosh for the Caledonian Railway (CR) and introduced in 1896. Taking their name from the estate in Perthshire owned by the Caledonian’s then deputy chairman, J.C.Bunten, all survived to be absorbed by the London, Midland and Scottish Railway (LMS) in 1923 and a few survived into British Railways (BR) ownership in 1948.