Baron St Levan, of St Michael's Mount in the County of Cornwall, is a title in the Peerage of the United Kingdom. It was created on 4 July 1887 for the former Member of Parliament Sir John St Aubyn, 2nd Baronet. He had previously represented Cornwall West in House of Commons as a Liberal and St Ives as a Liberal Unionist. He was succeeded by his eldest son, the second Baron. He was a Colonel and Honorary Brigadier-General in the Grenadier Guards. On his death the titles passed to his nephew, the third Baron. He was the son of the Hon. Sir Arthur James Dudley Stuart St Aubyn (1867–1897), second son of the first Baron. The third baron was succeeded in 1978 by his eldest son, the fourth baron. Before inheriting the peerage the fourth baron served with the Royal Navy at Dunkirk and in a minesweeper in Arctic Convoys during World War II and was awarded the Distinguished Service Cross (DSC). As of 2014, the titles are held by the latter's son, the fifth Baron, who succeeded in 2013.
The St Aubyn Baronetcy, of St Michael's Mount in the County of Cornwall, was created in the Baronetage of the United Kingdom in 1866 for the first Baron's father, Edward St Aubyn. He was the illegitimate son of Sir John St Aubyn, 5th Baronet, of Clowance, on whose death in 1839 the baronetcy of Clowance had become extinct (see St Aubyn Baronets).