William Boyd, 4th Earl of Kilmarnock (12 May 1705 – 18 August 1746), was a Scottish peer who joined the 1745 Jacobite Rising, was captured at Culloden and subsequently executed for treason on Tower Hill. His family were supporters of the government and Kilmarnock had not previously been involved with the Stuarts; he later stated "for the two Kings and their rights, I cared not a farthing which prevailed; but I was starving."