A king cake (sometimes rendered as kingcake or kings' cake) is a type of cake associated with the festival of Epiphany in the Christmas season in a number of countries, and in other places with Mardi Gras and Carnival. It is popular in Christmas season in France, Belgium and Switzerland (galette/gâteau des Rois), Portugal (Bolo Rei), Spain (Roscón de Reyes and in Catalonia called tortell), Greece and Cyprus (vasilopita) and Bulgaria (banitsa). In the United States, which celebrates Carnival ranging from Mobile, Alabama to East Texas, centered on New Orleans it is associated instead with Mardi Gras season traditions.
The cakes have a small trinket (often a small plastic baby, sometimes said to represent Baby Jesus) inside, and the person who gets the piece of cake with the trinket has various privileges and obligations.
In southern U.S.A., the tradition was brought to the area by colonists from France and Spain. King cake parties in New Orleans are documented back to the eighteenth century.