A Gatsby is a South African submarine sandwich consisting of a bread roll filled with chips and a choice of fillings and sauces. It originated in Cape Town and is popular throughout the Western Cape province. The sandwich is typically large and shared by several people.

A submarine sandwich, commonly known as a sub, hoagie, hero, Italian, grinder, wedge, or a spuckie, is a type of American cold or hot sandwich made from a cylindrical bread roll split lengthwise and filled with meats, cheeses, vegetables, and condiments.