His father, John Letablere Litton (1903–1941), served as a gunner in the Hong Kong Volunteer Defence Corps. He was killed in action on 18 December 1941 defending Hong Kong from Japanese attack, and was buried in Stanley Military Cemetery. His mother Enid Tak-ching Lo-Litton was a tennis player and won thirteen Hong Kong National Championships over a 24-year span. John's maternal uncle was the lawyer Sir Lo Man-kam, part of a prominent Eurasian family.