Brought up a Roman Catholic, Dillon conformed to the Church of England in 1767. In 1770 he was returned unopposed on Lord Abingdon’s interest at Westbury. He voted with Administration over Brass Crosby, 27 Mar. 1771. On 22 Jan. 1772 he supported the Address in a ‘short but elegant complimentary speech’,1Cavendish’s ‘Debates’, Egerton 231, p. 205. his only one on record. On 6 Feb. he voted against Sir William Meredith’s motion for relief from subscription to the 39 Articles.2Walpole, Last Jnls, i. p. 13, incorrectly dating the debate 7 Feb. He was again with Administration over the royal marriage bill, March 1772, and the Middlesex election motion, 26 Apr. 1773; and when on 25 Feb. 1774 he voted with Opposition in favour of making Grenville’s Election Act permanent he was classed in the King’s list as one of those who ‘generally vote with and are friends’. He does not appear to have sought re-election in 1774.
In 1789 he refused the offer of an Irish earldom but pressed for a British peerage.3For his ambition to obtain ‘a peerage one day or other’, see Ld. Suffolk to the King. 4 Oct. 1772, Fortescue, ii. 398. He wrote to Pitt, 12 Feb. 1795:4Chatham mss. ‘I have constantly served the King as far as I was able in the English House of Commons, and in and out of Parliament, in this country [Ireland].’ In 1799 his Irish estates were stated to be worth £20,000 p.a.5CP.
Dillon died 9 Nov. 1813.