William (1906-1967) was a son of Angus Mackenzie and Mary Maclennan, 3 Arivruach. William was educated in Tarbert, Harris from 1911 to 1930 and then at Glasgow University from 1931 to 1933. He then attended New College, Edinburgh. He was assistant in Stornoway High Church from 1940 to 1945 and then in Barvas from 1947 to 1950. He was licensed by the Presbytery of Lewis on 21 April 1953 and ordained and inducted into Berneray on 5 December 1956. Whilst serving on Berneray, he and his wife lived at the UFC Manse in Church Road. William was then transferred and inducted into Park on 12 June 1963.

He married Jessie Macfarlane of 8 New Road, Cross, Ness.