Leigh Hunt was educated at Christ's Hospital from 1791 to 1799, a period which is detailed in his autobiography. He entered the school shortly after Samuel Taylor Coleridge and Charles Lamb had both left; Thomas Barnes, however, was a school friend of his. One of the current boarding houses at Christ's Hospital is named after him. As a boy, he was an ardent admirer of Thomas Gray and william Collins, writing many verses in imitation of them. A speech impediment, later cured, prevented his going to university. "For some time after I left school," he says, "I did nothing but visit my school-fellows, haunt the book-stalls and write verses." His poems were published in 1801 under the title of Juvenilia, and introduced him into literary and theatrical society. He began to write for the newspapers, and published in 1807 a volume of theatre criticism, and a series of Classic Tales with critical essays on the authors.

In 1808 he left the War Office, where he had been working as a clerk, to become Editor of the Examiner, a newspaper founded by his brother, John. His brother Robert Hunt, among others, also contributed to its columns; his criticism earned the enmity of william Blake, who described the journal's office at Beaufort Buildings, Strand, London, as containing a "nest of villains". Blake's response included Leigh Hunt, who aside from publishing the vitriolic reviews of 1808 and 1809 had added Blake's name on a list of "quacks".

In 1809, Leigh Hunt married Marianne Kent (whose parents were Thomas and Ann). Over the next 20 years they had ten children: Thornton Leigh (1810–73), John Horatio Leigh (1812–46), Mary Florimel Leigh (1813–49), Swinburne Percy Leigh (1816–27), Percy Bysshe Shelley Leigh (1817–99), Henry Sylvan Leigh (1819–76), Vincent Leigh (1823–52), Julia Trelawney Leigh (1826–72), Jacyntha Leigh (1828–1914), and Arabella Leigh (1829–30).

In 1810–1811 he edited a quarterly magazine, the Reflector, for his brother John. He wrote "The Feast of the Poets" for this, a satire, which offended many contemporary poets, particularly william Gifford of the Quarterly.

This journal soon acquired a reputation for unusual political independence; it would attack any worthy target, "from a principle of taste," as John Keats expressed it. In 1813, an attack on the Prince Regent, based on substantial truth, resulted in prosecution and a sentence of two years' imprisonment for each of the brothers — Leigh Hunt served his term at the Surrey County Gaol. Leigh Hunt's visitors in prison included Lord Byron, Thomas Moore, Lord Brougham, Charles Lamb and others, whose acquaintance influenced his later career. The stoicism with which Leigh Hunt bore his imprisonment attracted general attention and sympathy. His imprisonment allowed him many luxuries and access to friends and family, and Lamb described his decorations of the cell as something not found outside a fairy tale. When Jeremy Bentham called on him, he was found playing battledore.

A number of essays in The Examiner that were written by Hunt and william Hazlitt between 1814 and 1817 under the series title "The Round Table" were collected in book form in The Round Table, published in two volumes in 1817. Twelve of the fifty-two essays were by Hunt, the rest by Hazlitt.

In 1816 he made a mark in English literature with the publication of Story of Rimini, based on the tragic episode of Francesca da Rimini told in Dante's Inferno. Hunt's preference was decidedly for Chaucer's verse style, as adapted to modern English by John Dryden, in opposition to the epigrammatic couplet of Alexander Pope which had superseded it. The poem is an optimistic narrative which runs contrary to the tragic nature of its subject. Hunt's flippancy and familiarity, often degenerating into the ludicrous, subsequently made him a target for ridicule and parody.

In 1818 appeared a collection of poems entitled Foliage, followed in 1819 by Hero and Leander, and Bacchus and Ariadne. In the same year he reprinted these two works with The Story of Rimini and The Descent of Liberty with the title of Poetical Works, and started the Indicator, in which some of his best work appeared. Both Keats and Shelley belonged to the circle gathered around him at Hampstead, which also included william Hazlitt, Charles Lamb, Bryan Procter, Benjamin Haydon, Charles Cowden Clarke, C.W. Dilke, Walter Coulson and John Hamilton Reynolds. This group was known as the Hunt Circle, or, pejoratively, as the Cockney School. Hunt was a man of varied talents, however. As a poet, he played a major role in freeing the couplet from the rigidity of neoclassical practice. He had remarkable insights as a literary critic and discovered and introduced to the public many poets, among them John Keats, Percy Bysshe Shelley, Robert Browning, and Alfred Tennyson. He encouraged many other Writers, such as Charles Lamb, william Hazlitt, Walter Savage Landor, and Charles Dickens. He was a Journalist of note, being Editor of the influential Examiner from its inception in 1808 to his departure for Italy in 1821. He was also Editor of several journals, and wrote for many more. Perhaps as a prose Writer he was best as an Essayist and has probably had more influence on the development of the personal essay than any other Writer. But he was also the author of a novel and several plays, two of which, A Legend of Florence and Lovers' Amazements, were produced (in 1840 and 1858, respectively). His varied literary achievements are sufficiently important to make him preeminent among secondary Writers of the Romantic period.

In 1819–1821, Hunt edited The Indicator, a weekly literary periodical published by Joseph Appleyard. Hunt probably wrote much of the content as well, which included reviews, essays, stories, and poems.

After Shelley's departure for Italy in 1818, Leigh Hunt became even poorer, and the prospects of political reform less satisfactory. Both his health and that of his wife failed, and he was obliged to discontinue the Indicator (1819–1821), having, he says, "almost died over the last numbers." Shelley suggested that Hunt go to Italy with him and Byron to establish a quarterly magazine in which Liberal opinions could be advocated with more freedom than was possible at home. An injudicious suggestion, it would have done little for Hunt or the Liberal cause at the best, and depended entirely upon the co-operation of the capricious, parsimonious Byron. Byron's principal motive for agreeing appears to have been the expectation of acquiring influence over the Examiner, and he was mortified to discover that Hunt was no longer interested in the Examiner. Leigh Hunt left England for Italy in November 1821, but storm, sickness and misadventure delayed his arrival until 1 July 1822, a rate of progress which Thomas Love Peacock appropriately compares to the navigation of Ulysses.

The death of Shelley, a few weeks later, destroyed every prospect of success for the Liberal. Hunt was now virtually dependent upon Byron, who did not relish the idea of being patron to Hunt's large and troublesome family. Byron's friends also scorned Hunt. The Liberal lived through four quarterly numbers, containing contributions no less memorable than Byron's "Vision of Judgment" and Shelley's translations from Faust; but in 1823 Byron sailed for Greece, leaving Hunt at Genoa to shift for himself. The Italian climate and manners, however, were entirely to Hunt's taste, and he protracted his residence until 1825, producing in the interim Ultra-Crepidarius: a Satire on william Gifford (1823), and his translation (1825) of Francesco Redi's Bacco in Toscana.

In 1825 a litigation with his brother brought him back to England, and in 1828 he published Lord Byron and some of his Contemporaries, a corrective to idealized portraits of Byron. The public was shocked that Hunt, who had been obliged to Byron for so much, would "bite the hand that fed him" in this way. Hunt especially writhed under the withering satire of Moore. For many years afterwards, the history of Hunt's life is a painful struggle with poverty and sickness. He worked unremittingly, but one effort failed after another. Two journalistic ventures, the Tatler (1830–1832), a daily devoted to literary and dramatic criticism, and Leigh Hunt's London Journal (1834–1835), were discontinued for want of subscribers, although the latter contained some of his best writing. His editorship (1837–1838) of the Monthly Repository, in which he succeeded william Johnson Fox, was also unsuccessful. The adventitious circumstances which allowed the Examiner to succeed no longer existed, and Hunt's personality was unsuited to the general body of readers.

In 1828 from January to July, Hunt edited The Companion, a weekly literary periodical published by Hunt and Clarke. The journal dealt with books, theatrical productions and Miscellaneous topics.

In 1832 a collected edition of his poems was published by subscription, the list of subscribers including many of his opponents. In the same year was printed for private circulation Christianism, the work afterwards published (1853) as The Religion of the Heart. A copy sent to Thomas Carlyle secured his friendship, and Hunt went to live next door to him in Cheyne Row in 1833. Sir Ralph Esher, a romance of Charles II's period, had a success, and Captain Sword and Captain Pen (1835), a spirited contrast between the victories of peace and the victories of war, deserves to be ranked among his best poems. In 1840 his circumstances were improved by the successful representation at Covent Garden of his play Legend of Florence. Lover's Amazements, a comedy, was acted several years afterwards, and was printed in Leigh Hunt's Journal (1850–1851); other plays remained in manuscript. In 1840 he wrote introductory notices to the work of Sheridan and to Edward Moxon's edition of the works of william Wycherley, william Congreve, John Vanbrugh and George Farquhar, a work which furnished the occasion of Macaulay's essay on the Dramatists of the Restoration. The narrative poem The Palfrey was published in 1842.

The time of Hunt's greatest difficulties was between 1834 and 1840. He was at times in absolute poverty, and his distress was aggravated by domestic complications. By Macaulay's recommendation he began to write for the Edinburgh Review. In 1844 Mary Shelley and her son, on succeeding to the family estates, settled an annuity of £120 upon Hunt (Rossetti 1890); and in 1847 Lord John Russell procured him a pension of £200. Now living in improved comfort, Hunt published the companion books, Imagination and Fancy (1844), and Wit and Humour (1846), two volumes of selections from the English poets, which displayed his refined, discriminating critical tastes. His book on the pastoral poetry of Sicily, A Jar of Honey from Mount Hybla (1848), is also delightful. The Town (2 vols., 1848) and Men, Women and Books (2 vols., 1847) are partly made up from former material. The Old Court Suburb (2 vols., 1855; ed. A Dobson, 2002) is a Sketch of Kensington, where he long resided. In 1850 he published his Autobiography (3 vols.), a naive and affected, but accurate, piece of self-portraiture. A Book for a Corner (2 vols.) was published in 1849, and his Table Talk appeared in 1851. In 1855 his narrative poems, original and translated, were collected under the title Stories in Verse.

Leigh Hunt was the original of Harold Skimpole in Bleak House. "Dickens wrote in a letter of 25 September 1853, 'I suppose he is the most exact portrait that was ever painted in words! ... It is an absolute reproduction of a real man'; and a contemporary critic commented, 'I recognized Skimpole instantaneously; ... and so did every person whom I talked with about it who had ever had Leigh Hunt's acquaintance.'" G. K. Chesterton suggested that Dickens "may never once have had the unfriendly thought, 'Suppose Hunt behaved like a rascal!'; he may have only had the fanciful thought, 'Suppose a rascal behaved like Hunt!'" (Chesterton 1906).

His Poetical Works (2 vols.), revised by himself and edited by Lee, were printed at Boston in 1857, and an edition (London and New York) by his son, Thornton Hunt, appeared in 1860. Among volumes of selections are Essays (1887), ed. A Symons; Leigh Hunt as Poet and Essayist (1889), ed. C Kent; Essays and Poems (1891), ed. RB Johnson for the "Temple Library."

His Autobiography was revised shortly before his death, and edited (1859) by his son Thornton Hunt, who also arranged his Correspondence (2 vols., 1862). Additional letters were printed by the Cowden Clarkes in their Recollections of Writers (1878). The Autobiography was edited (2 vols., 1903) with full bibliographical note by Roger Ingpen. A bibliography of his works was compiled by Alexander Ireland (List of the Writings of william Hazlitt and Leigh Hunt, 1868). There are short lives of Hunt by Cosmo Monkhouse ("Great Writers," 1893) and by RB Johnson (1896). Oxford Dictionary of National Biography Volume 28 (2004).