The Filet-O-Fish was introduced in 1962 as McDonald’s first menu item created for a regional market.
Franchise owner Lou Groen developed the sandwich for customers in heavily Catholic areas of Cincinnati, Ohio. During Lent, many Catholic customers avoided meat on Fridays, and Groen’s restaurants faced a sharp drop in sales. A fish sandwich offered a way to serve those customers while preserving the restaurant’s fast-food format.
The sandwich became more than a local solution. After testing and approval, McDonald’s added the Filet-O-Fish to its broader menu, where it became a long-running branded product.
The Filet-O-Fish is often confused with the Big Mac as an early signature item, but the Big Mac was introduced later, in 1967. The sandwich also illustrates how McDonald’s adapted its standardized brand to local religious and cultural circumstances.