William Prynne (1600 - October 24, 1669) was a Puritan opponent of the church policy of Archbishop of Canterbury William Laud. Born at Swanswick, near Bath, Somerset, he died at London. After graduating in law from Oxford University, he began a series of attacks on the current Arminian high church policies of the government, and on the (by Puritan standards) lax morals prevalent at Court. Being, like many Puritans, strongly opposed to stage plays, he included in his turgid Histriomastix, a denunciation of actresses which was widely felt to be an attack of Queen Henrietta Maria. He was tried in the Star Chamber in 1633 and sentenced to imprisonment and the removal of part of his ears. He was, however, able to continue his activities from prison, and was sentenced in 1637 to the removal of the rest of his ears and to be branded with letters S L (seditious libeller). He affected that these in fact stood for stigmata Laudis (the marks of Laud).

He was released by the Long Parliament, and supported the Parliamentary cause in the English Civil War. He was able to have the satisfaction of overseeing the trial of Laud, which eventually ended in the latter's execution. The tide of opinion was moving fast, and Prynne, having been at the forefront of radical opposition, now found himself a conservative figure, defending Presbyterianism against the Independents favoured by Oliver Cromwell and the army.

He became a thorn in Cromwell's side, and was imprisoned from 1650 to 1653 for his opposition to military government. Eventually, he supported the restoration of Charles II, and was rewarded with public office: he became the keeper of records in the Tower of London and was apparently a model civil servant.