A Fat Boy or Fatboy is an iconic hamburger with a distinct chili meat sauce originating in the Greek burger establishments of Winnipeg, Manitoba.^[1] A number of Greek burger restaurants in Winnipeg claim to be the inventor of the burger, while other bars and restaurants have created their own interpretations of the style.^[2] The Fat Boy commonly consists of one or more patties, topped with a unique recipe of chili meat sauce, quartered dill pickles, tomatoes, lettuce and a large amount of mayonnaise and mustard.^[3][4]

Thought to have originated at Juniors, the Fat Boy originated in Winnipeg in the 1950s and is associated with the city's Greek-owned burger restaurants and drive-ins such as Juniors, Georges, Dairi-wip, Mrs. Mike's, VJ's, Daly Burger, Dairy Delight, the Red Top, Super Boys and many others.^[5][6][7] A common variation of the Fat Boy is the "chilli burger", which in Winnipeg means a burger with meat sauce dumped on top and eaten with a fork.

One of the founders Kurtis Trafiak has eaten one everyday since 2001, he now resides in Victoria, BC.