He was born at Whitton, in the parish of Twickenham, Middlesex, and baptized there on 10 February 1609. His father, Sir John Suckling, was Secretary of State under James I and Comptroller of the Household of Charles I, and his mother was Elizabeth Cranfield, sister of Sir Lionel Cranfield, 1st Earl of Middlesex. The poet inherited his father's estate at the age of eighteen. He went to Trinity College, Cambridge, in 1623, and was enrolled at Gray's Inn in 1627. He was intimate with Thomas Carew, Richard Lovelace, Thomas Nabbes and especially with John Hales and Sir William Davenant, who later furnished John Aubrey with information about his friend.

In 1628 he left London to travel in France and Italy, returning before the autumn of 1630, when he was knighted. In 1631 he volunteered for the force raised by the Marquess of Hamilton to serve under Gustavus Adolphus in Germany. He was back at Whitehall in May 1632; but during his short service he had been present at the Battle of Breitenfeld and in many sieges. His poetic talent was only one of many accomplishments, but it commended him especially to Charles I and his queen, Henrietta Maria. He says of himself ("A Sessions of the Poets") that he "prized black eyes or a lucky hit at bowls above all the trophies of wit." Aubrey says that he invented the game of Cribbage, and relates that his sisters came weeping to the bowling green at Piccadilly to dissuade him from play, fearing that he would lose their portions. Suckling was so passionately devoted to cards, that he would frequently spend the whole morning in bed with a pack before him, studying the subtleties of his favourite games. He was considered not only the most skilful card-player, but also the best bowler in England.

In 1634 great scandal was caused in his old circle by a beating which he received at the hands of Sir John Digby, a rival suitor for the hand of the daughter of Sir John Willoughby; and it has been suggested that this incident, which is narrated at length in a letter (10 November 1634) from George Garrard to Strafford, had something to do with his beginning to seek more serious society. In 1635 he retired to his country estates in obedience to the proclamation of 20 June 1632 enforced by the Star Chamber against absentee landlordism, and employed his leisure in literary pursuits. In 1637 "A Sessions of the Poets" was circulated in manuscript, and about the same time he wrote a tract on Socinianism entitled An Account of Religion by Reason (pr. 1646).

At the breaking out of disturbances in 1639, when the Scottish Covenanters advanced to the English borders, many of the courtiers complimented the king, by raising forces at their own expense. Among these, none was more distinguished than Sir John Suckling. These gallant gentlemen vied with each other in the costly equipment of their forces, which led the king facetiously to remark, that "the Scots would fight stoutly, if only for the Englishmen's fine clothes." The troop of horse raised by Sir John alone cost him, so richly was it accoutred, twelve thousand pounds. In the action which ensued, the sturdy Scots were more than a match for the showy Englishmen; and among those who particularly distinguished themselves by their shabby behavior, was the splendid troop of Sir John Suckling. There is every reason to believe that Sir John personally acquitted himself as became a soldier and a gentleman; but the event gave rise to the following humorous pasquil, which, while some suppose it to have been written by Sir John Mennis, a cotemporary wit, others have attributed to Suckling himself.

As a dramatist Suckling is noteworthy as having applied to regular drama the accessories already used in the production of masques. His Aglaura (pr. 1638) was produced at his own expense with elaborate scenery. Even the lace on the actors' coats was of real gold and silver. The play, in spite of its felicity of diction, lacks dramatic interest, and the criticism of Richard Flecknoe (Short Discourse of the English Stage), that it seemed "full of flowers, but rather stuck in than growing there," is not altogether unjustified. The Goblins (1638, pr. 1646) has some reminiscences of The Tempest; Brennoralt, or the Discontented Colonel (1639, pr. 1646) is a satire on the Scots, who are the Lithuanian rebels of the play; a fourth play, The Sad One, was left unfinished owing to the outbreak of the Civil War. Suckling raised a troop of a hundred horse, at a cost of £12,000, and accompanied Charles on the Scottish expedition of 1639. He shared in the earl of Holland's retreat before Duns, and was ridiculed in an amusing ballad (pr. 1656), in Musarum deliciae, "on Sir John Suckling's most warlike preparations for the Scottish war."

He was elected as member for Bramber for the opening session (1640) of the Long Parliament; and in that winter he drew up a letter addressed to Henry Jermyn, afterwards earl of St Albans, advising the king to disconcert the opposition leaders by making more concessions than they asked for. In May of the following year he was implicated in an attempt to rescue Strafford (Thomas Wentworth, 1st Earl of Strafford?) from the Tower and to bring in French troops to the king's aid. The plot was exposed by the evidence of Colonel George Goring, and Suckling fled beyond the seas. The circumstances of his short exile are obscure. He was certainly in Paris in the summer of 1641. One pamphlet related a story of his elopement with a lady to Spain, where he fell into the hands of the Inquisition. The manner of his death is uncertain, but Aubrey's statement that he put an end to his life by poison in May or June 1642 in fear of poverty is generally accepted.

Among the best known of his minor pieces are the "Ballade upon a Wedding," on the occasion of the marriage of Roger Boyle, afterwards Earl of Orrery, and Lady Margaret Howard, "I prithee, send me back my heart," "Out upon it, I have loved three whole days together," and "Why so pale and wan, fond lover?" from Aglaura. "A Sessions of the Poets," describing a meeting of the contemporary versifiers under the presidency of Apollo to decide who should wear the laurel wreath, is the prototype of many later satires.

A collection of Suckling's poems was first published in 1646 as Fragmenta aurea. The so-called Selections (1836) published by the Rev. Alfred Inigo Suckling (author of the History and Antiquities of Suffolk [1846–1848] with Memoirs based on original authorities and a portrait after Van Dyck) is really a complete edition of his works, of which WC Hazlitt's edition (1874; revised ed., 1892) is little more than a reprint with some additions. The Poems and Songs of Sir John Suckling, edited by John Gray and decorated with woodcut border and initials by Charles Ricketts, was artistically printed at the Ballantyne Press in 1896. In 1910 Suckling's works in prose and verse were edited by A. Hamilton Thompson. For anecdotes of Suckling's life see John Aubrey's Brief Lives (Clarendon Press ed., ii.242).