McDonald’s 1962 sandwich was the Filet-O-Fish.
The Filet-O-Fish was created by franchisee Lou Groen in Cincinnati, Ohio, where many customers observed meatless dietary practices on Fridays. Groen developed a fish sandwich to attract those customers during a period when hamburger sales were weaker.
McDonald’s added the sandwich to its national menu in 1963 after testing and comparing it with a competing meatless option. It became an important part of the chain’s product branding and later gained a supporting advertising character, Captain Crook, in McDonaldland.
The Filet-O-Fish is often confused with later branded sandwiches such as the McChicken or Big Mac. Its defining historical distinction is that it was McDonald’s early seafood product and was created to address a specific regional sales problem.