The Filet-O-Fish was introduced in 1965 as McDonald’s first fish sandwich.
McDonald’s franchisee Lou Groen created the sandwich in Cincinnati, Ohio, where many customers observed meatless Friday traditions. The original version used a breaded fish fillet, cheese, and tartar sauce on a bun. It gave the chain a menu option for customers who did not want a beef hamburger.
The Filet-O-Fish was initially tested in the Cincinnati market before being added to the national menu. Its introduction showed how local customer patterns could influence a product that later became a permanent part of McDonald’s branding and menu identity.
The sandwich is often mistaken for a later fish-themed promotion, but Filet-O-Fish is the established McDonald’s product name. The fish used in the sandwich has changed over the decades and can vary by market, while the branded name has remained consistent.