Duncan (born 1909) was the eldest child of Allan MacAskill and Mary MacLeod of 7 Borve. Duncan was a pupil at Berneray School between 1915 and 1923.

Duncan married Fanny MacAskill of 19 Kyles Scalpay, with whom he was to have four children.

Duncan was ordained as a Church of Scotland minister, serving in Portnalong until 1961, in Cannich until 1967, and finally in Bernera, Lewis. He retired to Smithton in Inverness in 1976.