Areopagitica; A speech of Mr. John Milton for the Liberty of Unlicenc'd Printing, to the Parlament of England is a 1644 prose polemic by the English poet, scholar, and polemical author John Milton opposing licensing and censorship. Areopagitica is among history's most influential and impassioned philosophical defences of the principle of a right to freedom of speech and expression. Many of its expressed principles have formed the basis for modern justifications.

John Milton (9 December 1608 – 8 November 1674) was an English poet and intellectual who served as a civil servant for the Commonwealth of England under its Council of State and later under Oliver Cromwell. He wrote at a time of religious flux and political upheaval, and is best known for his epic poem Paradise Lost (1667). Written in blank verse, Paradise Lost is widely considered to be one of the greatest works of literature ever written.Writing in English, Latin, and Italian, he achieved international renown within his lifetime; his celebrated Areopagitica (1644), written in condemnation of 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 into his style: he introduced new words (coined from Latin and Ancient Greek) to the English language, and was the first modern writer to employ unrhymed verse outside of the theatre or translations.

William Hayley's 1796 biography called him the "greatest English author", and he remains generally regarded "as one of the pre-eminent 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". Poets such as William Blake, William Wordsworth and Thomas Hardy revered him.