Stephen Joseph Campbell was born to Tiburtio A. Campbell and his wife, Maria dos Santos, in Moruca, British Guiana, on December 26, 1897. Both of Campbell's parents died when he was young, and he was subsequently raised by his grandmother. He was brought up as a devout Catholic. He studied at Santa Rosa Mission School, and subsequently worked for many years as a teacher and as a catechist in various regions of Guyana. Campbell married Umbelina Da Silva on 9 February 1928.