McDonald's first sold the Filet-O-Fish sandwich in 1962.
The sandwich was created for McDonald's restaurants in areas where customers observed meat-free religious eating traditions, especially on Fridays. Franchisee Lou Groen developed the product in Cincinnati, where his restaurant faced a sharp drop in Friday sales. The fish sandwich gave McDonald's a branded menu item that could attract customers who might otherwise avoid hamburgers on particular days.
The Filet-O-Fish is sometimes dated to the moment it became a nationwide staple, but 1962 is the year it was introduced at McDonald's. Its fish variety and sourcing have changed over time, while the sandwich's name and basic identity have remained closely associated with the chain's menu branding.