1912 edition of the poem, illustrated by Jessie Willcox Smith.

"A Visit from St. Nicholas", also known as "The Night Before Christmas" and "Twas the Night Before Christmas" from its first line, is a poem first published anonymously in 1823 and generally attributed to Clement Clarke Moore.

The poem, which has been called "arguably the best-known verses ever written by an American", is largely responsible for some of the conceptions of Santa Claus from the mid-nineteenth century to today. Prior to the poem, American ideas about St. Nicholas and other Christmastide visitors varied considerably.