John Milton (9 December 1608 – 8 November 1674) was an English poet, polemicist, and civil servant. His 1667 epic poem Paradise Lost was written in blank verse and included 12 books, written in a time of immense religious flux and political upheaval. It addressed the fall of man, including the temptation of Adam and Eve by the fallen angel Satan, and God's expulsion of them from the Garden of Eden. Paradise Lost elevated Milton's reputation as one of history's greatest poets. He also served as a civil servant for the Commonwealth of England under its Council of State and later under Oliver Cromwell.

Milton achieved fame and recognition during his lifetime. His celebrated Areopagitica (1644) condemning pre-publication censorship is among history's most influential and impassioned defences of freedom of speech and freedom of the press. His desire for freedom extended beyond his philosophy and was reflected in his style, which included his introduction of new words to the English language, coined from Latin and Ancient Greek. He was the first modern writer to employ unrhymed verse outside of the theatre or translations.

Milton is described as the "greatest English author" by his biographer William Hayley, and he remains generally regarded "as one of the preeminent writers in the English language", though critical reception has oscillated in the centuries since his death, often on account of his republicanism. Samuel Johnson praised Paradise Lost as "a poem which ... with respect to design may claim the first place, and with respect to performance, the second, among the productions of the human mind", though he (a Tory) described Milton's politics as those of an "acrimonious and surly republican". Milton was revered by poets such as William Blake, William Wordsworth, and Thomas Hardy.

Phases of Milton's life parallel the major historical and political divisions in Stuart England at the time. In his early years, Milton studied at Christ's College at the University of Cambridge, and then travelled, wrote poetry mostly for private circulation, and launched a career as pamphleteer and publicist under Charles I's increasingly autocratic rule and Britain's breakdown into constitutional confusion and ultimately civil war. He was once considered dangerously radical and heretical, but he contributed to a seismic shift in accepted public opinions during his life that ultimately elevated him to public office in England. The Restoration of 1660 and his loss of vision later deprived Milton of much of his public platform, but he used the period to develop many of his major works.

Milton's views developed from extensive reading, travel, and experience that began with his days as a student at the University of Cambridge in the 1620s and continued through the English Civil War, which started in 1642 and continued until 1651. By the time of his death in 1674, Milton was impoverished and on the margins of English intellectual life but famous throughout Europe and unrepentant for political choices that placed him at odds with governing authorities.

John Milton is widely regarded as one of the greatest poets in English literature, though his oeuvre has drawn criticism from notable figures, including T. S. Eliot and Joseph Addison. According to some scholars, Milton was second in influence to none but William Shakespeare. In one of his books, Samuel Johnson praised him for having the power of "displaying the vast, illuminating the splendid, enforcing the awful, darkening the gloomy and aggravating the dreadful".