John McCaig was born in 1957 in Ayrshire.  

He was educated at Saint Joseph’s Academy, Kilmarnock, Heriot-Watt University, Edinburgh; the
Royal Scots College, Valladolid, Spain and the Pontifical University of Comillas.  He was ordained at the Good Shepherd Cathedral Ayr on 8 July 1983.  He was a Curate at the Church of Saint Peter in Chains till 1986 and the Church of Our Lady of the Assumption and Saint Meddan, Troon till 1987 when he left the priesthood.