Dillon, Edward (1739?–1809), catholic archbishop of Tuam, was born into a well-to-do family at Carna, near Ballinasloe, Co. Galway; nothing further has been ascertained of his family. He was presumably educated in France at the Irish college, Douai, of which he later became president. Of his early career as a priest nothing has been ascertained. On 8 December 1793 he was nominated co-adjutor to the bishop of Kilmacduagh, Laurence Nihill (1726–95), on whose death he succeeded to the see (29 June 1795). Dillon was content to be guided in his actions by the conservative Archbishop Troy (qv) and the Easter pastoral letter he issued on 6 April 1798 counselled against ‘the oaths and associations which have entailed so many misfortunes’ and warned of a possible ‘visit from the French’, who, having ‘intruded themselves’ elsewhere, had ‘pillaged and profaned’ churches as well as reviling and expropriating the papacy. An ecclesiastical anomaly or abuse (as he saw it) that he tried to rectify was the wardenship of Galway, an extra-diocesan jurisdiction. Like his predecessors he sought to annex it to Kilmacduagh, partly for financial reasons, but without success. On 19 November 1798 Dillon was translated to Tuam in succession to Boetius Egan (qv). As archbishop and metropolitan of Connacht he was a signatory to an episcopal resolution proposing a government veto on nominations to Irish catholic bishoprics (January 1799), although the proposal came to nothing.
Like the other catholic archbishops, Dillon was pro-union, believing that only union could restore peace and harmony to Ireland, though he only reluctantly signed a pro-union address, fearing he would be labelled ‘an Orange bishop’ (Keogh, 207). In 1800 he designated a newly ordained priest, Oliver Kelly (qv), to be president of a future diocesan college (St Jarlath's) and to organise its foundation. On Kelly he increasingly relied. With another priest, Boetius Egan, nephew of his predecessor, parish priest of Castlebar and dean of Tuam, Dillon quarrelled over money until Kelly mediated. During his last four years Dillon was in poor health and Kelly, by then vicar general, practically ran the diocese. Edward Dillon's income as archbishop was £497 in the period May 1799 to May 1800, and from his mensal parish (Tuam) £150 in 1801. His residence was a two-storey thatched house at Water Slade, Tuam. His death occurred at Abbeyland, Co. Cork, in August or September 1809 – on 20 August according to a document in the archives of the Congregatio Sacra de Propaganda Fide, Rome, though it was not reported in the Dublin Evening Post (the Dublin newspaper most read by catholics) until 19 September.