Lou Groen created the Filet-O-Fish in 1962 to attract Catholic customers who avoided meat on Fridays.
Groen operated a McDonald’s franchise in a heavily Catholic Cincinnati neighborhood. Friday meat abstinence reduced sales, so he developed a fish sandwich as an alternative. The product gave McDonald’s a branded menu item for a specific religious and seasonal need while broadening the company’s customer base.
The Filet-O-Fish was tested locally before gaining wider acceptance. Its fish fillet, bun, tartar sauce, and cheese became a recognizable combination associated with McDonald’s seafood offering.
The sandwich is sometimes incorrectly described as McDonald’s first specialty sandwich or as a product created by corporate headquarters. Its origin is specifically tied to Groen’s franchise and the 1962 Friday-sales problem.