John William Mackail OM FBA (26 August 1859 – 13 December 1945) was a Scottish academic of Oxford University and reformer of the British education system.

He is most often remembered as a scholar of Virgil and as the official biographer of the socialist artist William Morris, of whom he was a friend.

John Mackail, of the Free Church, and Louisa Irving, who was the youngest daughter of Aglionby Ross Carson FRSE, who was the rector of Edinburgh High School.

[1] He was educated at Ayr Academy; at Edinburgh University, from 1874 to 1877; and at Balliol College, Oxford, as Warner Exhibitioner, from 1877.

At Oxford, he took first classes in classical moderations (1879) and literae humaniores ('Greats') in 1881, and he also obtained the Hertford (1880), Ireland (1880), Newdigate (1881), Craven (1882) and Derby (1884) Prizes.