A graduate of the University of Cambridge and Queen’s University Belfast, Sir John was simultaneously called to the bar in England and Wales and in Northern Ireland in 1949. He became a QC in 1964.

He was appointed to the Northern Ireland High Court in 1973 and became a Lord Justice of Appeal in 1987, before retiring from the bench in 1998.

Sir John’s father, Baron MacDermott, served as Lord Chief Justice of Northern Ireland from 1951 to 1971.

The Bar of Northern Ireland told Irish Legal News that it learned of the passing of Sir John, who also served as chair of the Bar Council in 1971, “with sadness”.

“Together with his father Lord John MacDermott, a former Lord Chief Justice, the family involvement with the judiciary spanned more than half-a-century, with Sir John’s retirement from the Bench in 1998,” the Bar added.