Which McDonald's sandwich is shaped like a fish and was introduced for Lent?

The McDonald's sandwich shaped like a fish and introduced for Lent is the Filet-O-Fish. It was created in 1962 by franchise owner Lou Groen in Cincinnati, Ohio.

Groen's restaurant was in a predominantly Catholic neighborhood, where many customers avoided meat on Fridays. That practice caused hamburger sales to fall, especially during the Lenten season. Groen developed a fried fish sandwich with a bun, tartar sauce, and cheese to appeal to those customers.

Ray Kroc tested the Filet-O-Fish against his own meat-free Hula Burger, which used grilled pineapple. The fish sandwich won the sales trial and became McDonald's first non-hamburger menu item. It spread nationally in the United States during the 1960s.

The fish itself has changed over time and varies by market. U.S. versions have used Alaska pollock, while other countries have served hoki or other fish. “Fish Sandwich” describes the product informally, but Filet-O-Fish is the canonical brand name.