Stephen McGill was born on 4 January 1912 to Peter McGill and Charlotte Connolly in Glasgow, Scotland where he was educated at Holy Cross primary school and St Aloysius' College before entering the national junior seminary at St Mary's College, Blairs, Aberdeen.
Following his ordination he returned to France where he entered the novitiate of the Sulpicians at Issy-les-Moulineaux, Paris and was incardinated priest of St Sulpice (PSS) in July of the following year.
At this point the Second World War was under way in Europe so, following the fall of France to the Germans in June 1940, Father McGill, as a British citizen, had to make his escape via Marseille and Spain to avoid internment as an enemy alien.
During his time in Argyll and the Isles Bishop McGill attended sessions of the Second Vatican Council (1962 - 1965) and oversaw translation of the liturgy into Gaelic.
He died peacefully in his ninety fourth year on 9 November 2005 at Nazareth House, Cardonald, Glasgow.