Gerard Langbaine (15 July 1656 – 23 June 1692) was an English dramatic biographer and critic, best known for his An Account of the English Dramatic Poets (1691), the earliest work to give biographical and critical information on the playwrights of English Renaissance theatre. He is sometimes called Junior or the Younger to distinguish him from his father (1609–58) of the same name, a Doctor of Divinity who was Provost of Queens College, Oxford (1646–58) and Keeper of the University Archives.
The younger Langbaine was born in the parish of St. Peter-in-the-East, Oxford; his father's second son, he was apprenticed to a bookseller in St. Paul's Churchyard in London, but was sent to University after his older brother William died in 1672. He was educated at University College, Oxford, married, and settled in the neighborhood of Oxford. In 1690 he acquired a post at the University, as "yeoman bedel in arts," and in the following year was promoted to "esquire bedel of law and architypographus." (In his post as "architypographus" or printer, he issued an Appendix to the University Catalogue of Graduates.)
Langbaine's widow Mary remarried after his death, to a Rev. Smith.
Langbaine devoted his critical energies to the attempt to bring order and understanding to the stage drama of his era. He compiled A New Catalogue of English Plays (1688), in which he traced the sources of many plays of English Renaissance and Restoration drama, to the prose tales of Cinthio, Bandello, Belleforest and similar authors, and ultimately to classical sources. Langbaine has been called "the only serious scholar in this field for many years". By his own testimony (in A New Catalogue), Langbaine collected printed editions of 980 plays and masques, not counting drolls and interludes.
(Langbaine's Catalogue was first published in November 1687 under a false title, Momus Triumphans: or The Plagiaries of the English Stage, which mocked what others considered Langbaine's obsessive concern with plagiarism. In the correct edition that followed, Langbaine complained that "My friends may think me Lunatick." He blamed John Dryden for the trick, and became a determined enemy of the poet/dramatist.)