McDonald’s fish sandwich introduced in 1962 as an alternative to hamburgers is called the Filet-O-Fish.
The sandwich was created by Lou Groen, a McDonald’s franchise owner in Cincinnati, Ohio. Groen’s restaurant served a heavily Catholic area, where many customers avoided meat on Fridays, especially during Lent. To attract those customers, he developed a fish sandwich with a breaded fish fillet, tartar sauce, and cheese on a steamed bun.
McDonald’s founder Ray Kroc initially preferred a meatless sandwich based on pineapple, but the Filet-O-Fish outsold that option during a 1962 test. The sandwich then became a permanent menu item and was introduced across the United States in 1963.
The Filet-O-Fish is often grouped with burgers because it uses a bun and a sandwich-style construction, although its filling is fish rather than a beef patty. Its fish species and preparation have changed in different markets over time.