How the McDonald’s Filet-o-Fish became a Lenten tradition in the U.S.

A vintage McDonald’s Filet-O-Fish container with blue and green branding. / Credit: Karolis Kavolelis/Shutterstock

CNA Staff, Mar 21, 2025 / 06:00 am (CNA).

Few people associate McDonald’s with the season of Lent, but the fast-food chain has played a small but iconic role in Lenten history — at least in the United States.

Known primarily for its burgers and chicken nuggets, the restaurant’s “Filet-o-Fish” sandwich is also a classic mainstay on its menu — and it first arose in the early 1960s as a way to boost sales on Lenten Fridays. 

According to the company, Lou Groen, an early franchisee based in Cincinnati, ran a McDonald’s in a heavily Catholic neighborhood and observed a decrease in sales at his McDonald’s restaurant on Fridays during Lent. He proposed to founder Ray Kroc that he allow the restaurant to begin selling fish sandwiches as a way to draw in observant Catholics on Fridays.

Kroc was dubious about adding fish to the menu. Groen would later claim that Kroc told him: “I don’t want my stores stunk up with the smell of fish!”

He and Groen decided to run a test: They’d sell Groen’s fish sandwich on a Friday alongside what Kroc dubbed the “Hula Burger” — a meatless sandwich consisting of grilled pineapple with a slice of cheese on top. 

Perhaps unsurprisingly, the Filet-o-Fish won out. In fact, it won massively: In its corporate history McDonald’s says the fish sandwich sold 350 orders, while only six customers purchased a “Hula Burger.” 

A few years later, the fish sandwich was the first new dish officially added to the original McDonald’s menu. 

The company says it has since become a “popular menu item.” At one point McDonald’s even advertised the sandwich with an anthropomorphic, sharply dressed piece of cod known as “Phil A. O’Fish.” 

The sandwich remains an indelible part of American fast food culture, though it appears to have fallen somewhat out of favor in recent years: AllRecipes earlier this year polled a group of chefs about the “best fast-food fish sandwich,” and the Filet-o-Fish ranked 10 out of 11. Earlier this month, meanwhile, Taste of Home ranked the Filet-o-Fish at the bottom of its list of fast-food fishwiches. 

Still, due to its legendary roots, the Filet-o-Fish’s place in both fast-food and Catholic history is assured. Kroc himself must have been aware of its looming historicity in the early 1960s: McDonald’s says that he was so sure of the success of his Hula Burger that he “made a side bet with his first grillman Fred Turner that the loser would buy the winner a new suit.”

“Fred got a new suit,” company historian Mike Bullington said, “and McDonald’s got the Filet-O-Fish.”