Who invented the Filet-O-Fish for McDonald's?

Lou Groen invented the Filet-O-Fish for McDonald's.

Groen operated a McDonald's franchise in Cincinnati, Ohio, in a neighborhood with a large Catholic population. On Fridays during Lent, when many Catholics traditionally avoided meat, his restaurant's sales fell sharply. Groen responded by developing a fish sandwich to attract customers who wanted a meatless option.

The product was tested in 1962 in the Cincinnati area. Ray Kroc also tested a competing meatless sandwich, the Hula Burger, but the Filet-O-Fish sold better. McDonald's selected Groen's creation and added it to the national menu in 1963.

The sandwich became an important part of McDonald's branding because it broadened the chain's appeal beyond its hamburger identity. Its name clearly describes the product, making it distinct from the brand's more abstract or character-based marketing names.