Clement Clarke Moore (July 15, 1779 – July 10, 1863) was an American writer, scholar, and real estate developer, best known as the author of the Christmas poem "A Visit from St. Nicholas", which introduced the world to Santa Claus's reindeer. Moore's legacy extends beyond this festive poem; he was a distinguished 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, which continues to operate on land donated by Moore, is situated in Chelsea Square, an area developed on part of his large inherited estate in what is now the residential neighborhood of Chelsea.

Moore's influence was not limited to academia and literature; 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. His work in subdividing and developing his estate contributed significantly to the urban landscape of New York City.

The poem "A Visit from St. Nicholas," more commonly known by its opening line, 'Twas the Night Before Christmas, was first published anonymously in 1823. Moore publicly claimed authorship in 1837, and during his lifetime, his authorship was not disputed. However, a rival claim emerged later, leading scholars to engage in debates over the identity of the poem's true author, utilizing textual and handwriting analysis among other historical sources.