Which McDonald’s product name was created by franchisee Lou Groen in 1963?

Lou Groen created the Filet-O-Fish name and sandwich for McDonald’s in 1963.

Groen operated a McDonald’s franchise in a predominantly Catholic neighborhood in Cincinnati, Ohio. Because many customers avoided meat on Fridays, especially during Lent, he proposed a fish sandwich to attract business on that day.

The product was tested alongside a competing meatless sandwich and became the successful choice. McDonald’s later expanded the Filet-O-Fish beyond its original market, making its name part of the chain’s long-term menu branding.

The Filet-O-Fish is sometimes incorrectly treated as a later seafood variation. Its significance is that it was an early example of McDonald’s adapting a branded menu item to local religious and customer patterns.