Sir William Leighton (1752 – 23 April 1826) was a British shipowner and merchant who served as the Lord Mayor of London in 1806. Leighton's family was from County Durham in the North East of England and he moved to London around 1779 following his father's death. Leighton worked as a shipping coal from the port of Newcastle, and was based at Newcastle's . Because of his maritime interests, Leighton served on various shipping committees.