Thomas Jacomb (1622–1687) was an English ejected minister.
He was the son of John Jacombe of Burton Lazars, near Melton Mowbray, Leicestershire; Samuel Jacomb (d. 1659), his younger brother, was also a Puritan minister and popular preacher., was born in 1622. He was educated at Melton free school, and for two years under Edward Gamble at Newark grammar school. He matriculated at Magdalen Hall, Oxford, in the Easter term, 1640; and when the First English Civil War broke out moved to St John's College, Cambridge (28 October 1642), where he graduated B.A. in 1643. Shortly afterwards he signed the covenant, and became a fellow of Trinity College in place of an ejected royalist.
Jacomb completed his M.A. in 1647. In the same year he took Presbyterian orders, became chaplain to the Countess-dowager of Exeter, widow of David Cecil, 3rd Earl of Exeter, and received the living of St. Martin's, Ludgate Hill, on the sequestration of Dr. Michael Jermyn. He was appointed by parliament an assistant to the London commissioners for ejecting insufficient ministers and schoolmasters, and in 1659 he was made one of the triers of ministers.
Jacomb's opinions, however, were moderate, and on the Restoration he was created D.D. at Cambridge by royal mandate dated 19 November 1660, along with two other Presbyterian ministers, William Bates and Robert Wilde. He was named on the royal commission for the review of the prayer-book (25 March 1661), and was treated respectfully at the meetings. He was on the Presbyterian side, and took a leading part in drawing up the exceptions against the Book of Common Prayer. Samuel Pepys heard him preach on 14 April 1661 and 16 February 1661. He was ejected for nonconformity in 1662.