A Visit from St. Nicholas, more commonly 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 later attributed to Clement Clarke Moore, who claimed authorship in 1837.

The poem has been called "arguably the best-known verses ever written by an American" and is largely responsible for some of the conceptions of Santa Claus from the mid-nineteenth century to today. It has had a massive effect on the history of Christmas gift-giving. Before the poem gained wide popularity, American ideas had varied considerably about Saint Nicholas and other Christmastide visitors. A Visit from St. Nicholas eventually was set to music and has been recorded by many artists.