Matthew Arnold was born at Laleham. He attended Rugby himself, and then Balliol College, Oxford, becoming a Fellow of Oriel in 1845. Thereafter he was private secretary to Lord Lansdowne, Lord President of the Council, through whose influence he was in 1851 appointed as school inspector. Two years before this he had published his first book of poetry, The Strayed Reveller, which he soon withdrew: some of the poems, however, including "Mycerinus" and "The Forsaken Merman," were afterwards republished, and the same applies to his next book, Empedocles on Etna (1852), with "Tristram and Iseult." He was later appointed the Professor of Poetry at Oxford, an honor which, though it did not pay much, must have been of some vindication for Arnold who struggled to make his artistic mark and had never been a star pupil when he was a student there. Ironically, however, he coined the term "Dreaming Spires", which has become something of a catchphrase for Oxford.

He wrote most of his best-known poetry before the age of forty, after which he turned to literary and cultural criticism and theology. His principal writings are, in poetry, Poems (1853), containing "Sohrab and Rustum," and "The Scholar Gipsy;" Poems, 2nd Series (1855), containing "Balder Dead;" Merope (1858); New Poems (1867), containing "Thyrsis," an elegy on Arthur Hugh Clough, "A Southern Night," "Rugby Chapel," and "The Weary Titan". In prose he wrote On Translating Homer (1861 and 1862), On the Study of Celtic Literature (1867), Essays in Celtic Literature (1868), 2nd Series (1888), Culture and Anarchy (1869), St. Paul and Protestantism (1870), Friendship's Garland (1871), Literature and Dogma (1873), God and the Bible (1875), Last Essays on Church and Religion (1877), Mixed Essays (1879), Irish Essays (1882), and Discourses in America (1885). He also wrote some works on the state of education in mainland Europe. In 1883 he received a pension of £250. Never fully free from financial troubles (including his son's gambling debts), he left the same year for a lecture tour of America. There his daughter would fall in love and marry an American. Five years later, when racing to meet his daughter and new granddaughter, he would suffer a fatal heart attack. He is buried in All Saints' Churchyard, Laleham, Middlesex

His 1867 poem Dover Beach, depicted a nightmarish world from which the old religious verities have retroceded, is sometimes held up as an early, if not the first, example of the modern sensibility. In a famous preface to a selection of the poems of William Wordsworth, Arnold identified himself, a little ironically, as a "Wordsworthian." The influence of Wordsworth, both in ideas and in diction, is unmistakable in Arnold's best poetry.

Arnold is famous for introducing a methodology of literary criticism through his Essays in Criticism (1865, 1888) which influence critics to this day. Arnold believed that rules for an objective approach in literature criticism existed and argued that these rules should be followed by all critics.

He was led on from literary criticism to a more general critique of the spirit of his age. Between 1867 and 1869 he wrote Culture and Anarchy, famous for the term he popularised for a section of the Victorian era population: "Philistines", a word which derives its modern cultural meaning (in English - German-language usage was well established) from him. See philistinism.

His niece (daughter of his younger brother Thomas), Mary Augusta Arnold, was a novelist under her married name of Mrs Humphry Ward.

Arnold wrote during the Victorian period (1837–1901), and is sometimes called the third great Victorian poet, behind Alfred Tennyson, 1st Baron Tennyson and Robert Browning. Arnold himself was keenly aware of his place in poetry, and in an 1869 letter to his mother, discussed the merits of his work and his two more famous peers: "My poems represent, on the whole, the main movement of mind of the last quarter of a century, and thus they will probably have their day as people become conscious to themselves of what that movement of mind is, and interested in the literary productions which reflect it. It might be fairly urged that I have less poetic sentiment than Tennyson, and less intellectual vigour and abundance than Browning. Yet because I have more perhaps of a fusion of the two than either of them, and have more regularly applied that fusion to the main line of modern development, I am likely enough to have my turn, as they have had theirs."

Some consider Arnold to be the bridge between Romanticism and Modernism. His use of symbolic landscapes was typical of the Romantic era, while his negative opinions towards everything was typical of the Modern era. The rationalistic tendency of certain of his writings gave offence to many readers, and the sufficiency of his equipment in scholarship for dealing with some of the subjects which he handled was called in question; but he undoubtedly exercised a stimulating influence on his time; his writings are characterised by the finest culture, high purpose, sincerity, and a style of great distinction, and much of his poetry has an exquisite and subtle beauty, though here also it has been doubted whether high culture and wide knowledge of poetry did not sometimes take the place of the true poetic fire. Henry James wrote that Matthew Arnold's poetry will appeal to those who "like their pleasures rare" and who like to hear the poet "taking breath."