Sir John St Aubyn, 5th Baronet, English politician (d. 1839)

Sir John St Aubyn, 5th Baronet (17 May 1758 – 10 August 1839), was a British Member of Parliament, High Sheriff of Cornwall and Grand Master of the Freemasons. Born in London, he succeeded to the baronetcy on 12 October 1772, at which point he inherited Clowance, the family's estate near Crowan, Cornwall.