Clement Clarke Moore (July 15, 1779 – July 10, 1863) was an American writer, scholar and real estate developer. He is best known as author of the Christmas poem "A Visit from St. Nicholas."

Moore was Professor of Oriental and Greek Literature, as well as Divinity and Biblical Learning, at the General Theological Seminary of the Protestant Episcopal Church, in New York City. The seminary was developed on land donated by Moore and it continues on this site at Ninth Avenue between 20th and 21st streets, in an area known as Chelsea Square. Moore gained considerable wealth by subdividing and developing other parts of his large inherited estate in what became known as the residential neighborhood of Chelsea. He also served for 44 years as a member of the board of trustees of Columbia College (later University), and was a board member of the New York Society Library and the New York Institution for the Blind.

"A Visit from St. Nicholas," which later became widely known by its opening line, "'Twas the Night Before Christmas," was first published anonymously in 1823. Moore publicly claimed authorship in 1837, and this was not disputed during his lifetime, but a rival claimant emerged later and scholars now debate the identity of the author, calling on textual and handwriting analysis as well as other historical sources.