He was the son of Sir Matthew Carew, master in chancery, and his wife, Alice Ingpenny, widow of Sir John Rivers, Lord Mayor of London. The poet was probably the third of the eleven children of his parents, and was born at West Wickham in Kent, in the early part of 1595; he was thirteen years old in June 1608, when he matriculated at Merton College, Oxford. He took his degree of B.A. early in 1611, and proceeded to study at the Middle Temple. Two years later his father complained to Sir Dudley Carleton that he was not doing well. He was therefore sent to Italy, as a member of Sir Dudley's household, and when the ambassador returned from Venice, he seems to have kept Thomas Carew with him, for he was working as secretary to Carleton, at the Hague, early in 1616. However, he was dismissed in the autumn of that year for levity and slander; he had great difficulty in finding another job. In August 1618 his father died, and Carew entered the service of Edward Herbert, Baron Herbert of Cherbury, in whose train he travelled to France in March 1619, and it is believed that he remained with Herbert until his return to England, at the close of his diplomatic missions, in April 1624. Carew "followed the court before he was of it," not receiving the definite commitment of the chamber until 1628.
While Carew held this office, he displayed his tact and presence of mind by stumbling and extinguishing the candle he was holding to light Charles I into the queen's chamber, because he saw that Lord St Albans had his arm round her majesty's neck. The king suspected nothing, and the queen heaped favours on the poet. Probably in 1630, Carew was made "server "or taster-in-ordinary to the king. To this period may be attributed his close friendships with Sir John Suckling, Ben Jonson and Edward Hyde, 1st Earl of Clarendon; the latter described Carew as "a person of pleasant and facetious wit." John Donne, whose celebrity as a court-preacher lasted until his death in 1631, exercised a powerful if not entirely healthy influence over the genius of Carew. In February 1633 a masque by the latter, Coelum Britanicum, was acted in the Banqueting House at Whitehall, and was printed in 1634.
The close of Carew's life is absolutely obscure. It was long supposed that he died in 1639, and this has been thought to be confirmed by the fact that the first edition of his Poems, published in 1640, seems to have a posthumous character. But Clarendon tells us that "after fifty years of life spent with less severity and exactness than it ought to have been, he died with the greatest' remorse for that licence." If Carew was more than fifty years of age, he must have died in or after 1645, and in fact there were final additions made to his Poems in the third edition of 1651. Walton tells us that Carew in his last illness, being afflicted with the horrors, sent in great haste to "the ever-memorable" John Hales (1584-1656); Hales "told him he should have his prayers, but would by no means give him then either the sacrament or absolution."
Carew's poems are sensuous lyrics. They open to us, in his own phrase, "a mine of rich and pregnant fancy." His metrical style was influenced by Jonson and his imagery by Donne, for whom he had an almost servile admiration. Carew had a lucidity and directness of lyrical utterance unknown to Donne. It is perhaps his greatest distinction that he is the earliest of the Cavalier song-writers by profession, of whom John Wilmot, Earl of Rochester, was a later example, poets who turned the disreputable incidents of an idle court-life into poetry which was often of the rarest delicacy and the purest melody and colour. The longest and best of Carew's poems, "A Rapture," would be more widely appreciated if the rich flow of its imagination were restrained by greater reticence of taste.