Guy Debenham was born in Scarborough, Yorkshire, on 27 January 1923, the second son of Leonard Snowden Debenham, a surgeon, and Anna Archer-Shee, a nurse and the daughter of a banker. He was educated at Stonyhurst and Edinburgh University. He did junior posts at Leith Infirmary, Worcester, Wolverhampton, Rochester, Gloucester, Swindon and Sheffield United Hospitals, falling under the influence of J K Monro, W J Lyttle, Bob Zachary and Frank Holdsworth. He did his National Service in the RAMC in the Middle East. He was married three times; firstly to Judy in 1949, she died the following year and secondly to Marjorie in 1954 and she died in 1982. His third wife, Diane, whom he married in 1984, survives him. He was a keen wood engraver and played the flute. He died on 1 December 2002 in Canada.