John Bourke, 4th Earl of Mayo, GCH, PC (Ire) (18 June 1766 – 23 May 1849) was an Irish peer and courtier, styled Lord Naas from 1792 until 1794. He was the eldest son of Joseph Deane Bourke, 3rd Earl of Mayo (Archbishop of Tuam 1782–94) and his wife, Elizabeth, daughter of Sir Richard Meade, 3rd Baronet. He succeeded to his father's titles on the death of his father on 20 August 1794. Before the Act of Union, he was Chairman of Committees in the Irish House of Lords; as compensation from the abolition of the House in 1801, he was awarded an annual pension of £1332. On 20 February 1810, he was sworn of the Privy Council of Ireland and was elected an Irish representative peer on 2 March 1816. On 11 May 1819, he represented the Duke of Clarence and St Andrews (later William IV) at the baptism