Santa Claus (also known as Saint Nicholas, Saint Nick, Father Christmas, Kris Kringle, Santy or simply Santa) is a folklore figure in various cultures who distributes gifts to children, normally on Christmas Eve. Each name is a variation of Saint Nicholas, but refers to Santa Claus.

Father Christmas is a well-loved figure in the United Kingdom, and is now interchangeable with Santa Claus, though the two had quite different origins. The term Santa is as widely used and understood by British children as Father Christmas.

Santa is a variant of a European folk tale based on the historical figure Saint Nicholas, a bishop from present-day Turkey, who supposedly gave presents to the poor. This inspired the mythical figure of Sinterklaas, the subject of a major celebration in the Netherlands (where his alledged birthday is celebrated), which in turn inspired both the myth and the name of Santa Claus.

He forms an important part of the Christmas tradition throughout the Western world as well as in Latin America and Japan and other parts of East Asia.

In many Eastern Orthodox traditions, Santa Claus visits children on New Year's Day and is identified with Saint Basil whose memory is celebrated on that day.

Depictions of Santa Claus also have a close relationship with the Russian character of Ded Moroz ("Grandfather Frost"). He delivers presents to children and has a red coat, fur boots and long white beard. Much of the iconography of Santa Claus could be seen to derive from Russian traditions of Ded Moroz, particularly transmitted into western European culture through his German folklore equivalent, Väterchen Frost.

Conventionally, Santa Claus is portrayed as a kindly, round-bellied, merry, bespectacled white man in a red coat trimmed with white fur, with a long white beard. On Christmas Eve, he rides in his sleigh pulled by flying reindeer from house to house to give presents to children. To enter the house, Santa Claus comes down the chimney and exits through the fireplace. During the rest of the year he lives together with his wife Mrs. Claus and his elves manufacturing toys. Some modern depictions of Santa (often in advertising and popular entertainment) will show the elves and Santa's workshop as more of a processing and distribution facility, ordering and receiving the toys from various toy manufacturers from across the world. His home is usually given as either the North Pole in the United States (Alaska), northern Canada, Korvatunturi in Finnish Lapland, Dalecarlia in Sweden, or Greenland, depending on the tradition and country. Sometimes Santa's home is in Caesarea when he is identified as Saint Basil.

Since most activities associated with Santa Claus are extraordinary, such as delivering presents to all of the believing children in one night, how he squeezes down chimneys, how he enters homes without chimneys, why he never dies, and how he makes reindeer fly, "magic" is usually used to explain his actions.