Thomas Tyrwhitt (March 27, 1730 - August 15, 1786) was an English classical scholar and critic.

He was born in London, where he also died. He was educated at Eton and Queen's College, Oxford (fellow of Merton, 1755). In 1756 he was appointed under-secretary at war, in 1762 clerk of the House of Commons. In 1768 he resigned his post, and spent the remainder of his life in learned retirement. In 1784 he was elected a trustee of the British Museum, to which he bequeathed a portion of his valuable library.

His principal classical works are:

• Fragmenta Plutarchi II. inedita (1773), from a Harleian manuscript
• Dissertatio de Babrio (1776), containing some fables of Aesop, hitherto unedited, from a Bodleian manuscript
• the pseudo-Orphic De lapidibus (1781), which he assigned to the age of Constantius
• Conjecturae in Strabonem (1783)
• Isaeus De Meneclis hereditate (1785)
• Aristotle's Poetica, his most important work, published after his death under the superintendence of Dr Burgess , bishop of Salisbury, in 1794.

Special mention is due of his editions of Chaucer's Canterbury Tales (1775-1778); and of Poems, supposed to have been written at Bristol by Thomas Rowley and others in the Fifteenth Century (1777-1778), with an appendix to prove that the poems were all the work of Chatterton.

In 1782 he published a Vindication of the Appendix in reply to the arguments of those who maintained the genuineness of the poems. While clerk of the House of Commons he edited Proceedings and Debates of the House of Commons, 1620-1621 from the original manuscript in the library of Queen's College, Oxford, and Henry Elsynge 's (1598-1654) The Manner of holding Parliaments in England.