Following his theological studies, Dix became a curate at St Saviour’s, St Albans and was ordained as a deacon in 1940 and as a priest in 1941. In 1943 he joined the Universities' Mission to Central Africa and was sent to the Zanzibar Diocese where he served as Priest in Charge of Msalabani (1944-51) and as a missionary in Tanga (1951-54). In 1954, Dix was appointed Archdeacon of Zanzibar and Priest in Charge of Christ Church Cathedral, Zanzibar. He conducted a service during an official visit to Zanzibar by Princess Margaret on October 7, 1956.