Barnard, Thomas (1727–1806), Church of Ireland bishop, was born in Surrey and baptised there on 22 February 1727, the eldest son of Dr William Barnard (1697–1768), bishop of Derry, and his wife, Anne (d. 1782), sister of the Irish primate George Stone (qv). Thomas was educated under Dr Nicholl at Westminster School before entering TCD as a fellow-commoner on 24 October 1744. He graduated BA in the spring of 1748, and subsequently attended Cambridge University, graduating MA in the summer of 1749. On his appointment to the archdeaconry of Derry on 3 June 1761, he was awarded the degree of DD by TCD. He was made dean of Derry in 1769 and bishop of Killaloe and Kilfenora in 1780, and in 1794 he was translated to the united sees of Limerick, Ardfert and Aghadoe.
Throughout his life Barnard maintained a keen interest in literature and culture. He was elected a member of the Royal Society on 29 May 1783, and he belonged to several other organisations, including the Literary Club. In this society he formed friendships with Edmund Burke (qv), Dr Johnson, Joshua Reynolds, and David Garrick. He is mentioned several times in Boswell's Life of Johnson, which records a well-known exchange between Johnson and Barnard. To commemorate the occasion Barnard wrote a poem entitled ‘Verses’, which appeared in several collections of poetry. He regularly corresponded with the clergyman and co-founder of Methodism, Charles Wesley, taking an interest in the musical careers of Wesley's sons. In 1785 he was closely involved in the founding of the RIA; with Sir Joseph Banks, he drew up the rules for the academy, and was an original member.
Barnard's first wife was Anne (d. 1803), daughter of William Browne of Browne's Hill, Co. Carlow, the niece and heir of Bishop Robert Clayton of Clogher. After her death, Barnard married Jane Ross-Lewin of Fort Fergus, Co. Clare, on 30 August 1803, who died shortly after their marriage. Three years later, Barnard died 7 June 1806 in Wimbledon, in the house of his only son, Andrew Barnard, husband of Lady Anne Barnard. He was buried in Westminster Abbey.
There are two portraits of Barnard in the National Portrait Gallery, London, and collections of his letters in the universities of Yale and Manchester.