Captain William Stewart Campbell was the son of Sir John Campbell, a leader in gynaecology in Ulster. His mother was one of the earliest women graduates in medicine in Belfast. he was educated at the Royal Belfast Academical Institution and graduated MB, BCh, BAO. at Queen's University, Belfast, with first-class honours in 1932. He had already taken the BSc. In 1937 he took the FRCS after a time spent as demonstrator in anatomy at his old university.
He held resident posts in obstetrics and gynaecology, but in 1941 was commissioned in the RAMC, where he served as a surgical specialist in Malta, Lebanon, and North Africa. After demobilisation with the rank of major, he took the MRCOG in 1947. In 1948 he was appointed to the obstetric staff of the Jubilee Maternity (Belfast City) Hospital, and was elected in 1950 to the staff of the Samaritan Hospital for Women, Belfast, where his father had served for many years. He became FRCOG in 1960.1