Professor Philip MacDonald Sheppard, F.R.S. (27 July 1921 – 17 October 1976) was a British geneticist and lepidopterist. He made advances in ecological and population genetics in lepidopterans, pulmonate land snails and humans. In medical genetics, he worked with Sir Cyril Clarke on Rh disease.

He was born on 27 July 1921 in Marlborough, Wiltshire, England and attended Marlborough College from 1935 to 1939.

• 1940 to 1945 - Royal Air Force Volunteer Reserve (prisoner-of-war from 1942 to 1945). Participated, as an earth-bearer, in one of the famous tunnel escapes; it is unclear whether this was the "Wooden Horse" escape, or the "Great" Escape^[1]
• 1946 to 1948 - Studied Zoology at Worcester College, University of Oxford.
• 1956 to 1959 - Lecturer at Liverpool University
• 1959 to 1962 - Reader at Liverpool University
• 1963 to 1976 - Professor of genetics at Liverpool University
• 18 March 1965 - FRS
• 1974 - Darwin Medal of the Royal Society
• 1975 - Linnean Medal (Gold Medal) for Zoology from the Linnean Society of London

Cyril Clarke answered an advert in an insect magazine for swallowtail butterfly pupa that had been placed by Sheppard. They met and began working together in their common interest of lepidopterology. They also worked on Rh disease.

In 1961 Sheppard started a colony of scarlet tiger moths by the Wirral Way, West Kirby, Merseyside, which were rediscovered in 1988 by Cyril Clarke, who continued to observe them in his retirement to study changes in the moth population.

Sheppard married Patricia Beatrice Lee in 1948. They had three sons. He died of acute leukemia on 17 October 1976.