John St Aubyn, 4th Baron Saint Levan

John Francis Arthur St Aubyn, 4th Baron St Levan OBE DSC DL (23 February 1919 – 7 April 2013) was a British hereditary peer, decorated Royal Navy officer, solicitor, and heritage figure. From 1978 to 2003, he was custodian of the family seat of St Michael's Mount in Cornwall.

Early life St Aubyn was born on 23 February 1919 in London, England. In 1938, he entered Trinity College, Cambridge to study for a degree. His university studies were interrupted by World War II and his military service. Having completed his training, he was posted to the Halcyon-class minesweeper HMS Salamander.