10 Facts You Didn't Know About McDonald's Filet-O-Fish Sandwich

McDonald's Filet-O-Fish is a sandwich unlike any other on their menu. A square-shaped fried fish patty, American cheese, and a dollop of McDonald's tartar sauce served on a steamed bun, its taste is unforgettable to anyone who's tried it. It's not one of McDonald's top-selling items in the U.S., but the Filet-O-Fish can still hold its own: news site Reckon reports that 300 million Filet-O-Fish sandwiches were sold in the U.S. in 2023 alone.

In addition to its unique taste and texture, a big part of the Filet-O-Fish's appeal is the fact that it's one of the few McDonald's items that can be eaten by just about anyone, regardless of dietary requirements, culture, or religion. No wonder it's a menu mainstay in many McDonald's restaurants around the world. Even if you don't count yourself among those who love the Filet-O-Fish, you've probably at least heard of it. But here are some facts even the Filet-O-Fish's biggest fans may not know.

Some of us could say we love food religiously, but some foods came about because of religion. That's the case for the Filet-O-Fish. In 1962, McDonald's franchise owner Lou Groen was losing money. Customers at his Cincinnati-based location loved the chain's delicious burgers, but they couldn't always eat them. The neighborhood was predominantly Catholic, and at the time, Catholics weren't allowed to eat meat on Fridays. If he wanted to make a profit, Groen would have to adapt to this rule.

Taking inspiration from local restaurants, he decided to create an alternative to hamburgers and settled on a fish sandwich that would eventually become the Filet-O-Fish we all know and love today. Now, all he had to do was run it by McDonald's president Ray Kroc, which didn't turn out the way Groen had hoped. Kroc didn't want to serve fish at McDonald's restaurants, but Groen was determined to change his mind.

When Lou Groen told McDonald's head honcho Ray Kroc about his new sandwich idea, Kroc was less than enthusiastic. He didn't want McDonald's to sell fish. For one thing, he was worried that cooking fish would make McDonald's restaurants smell bad. For another, creating a new sandwich meant finding new suppliers, figuring out the best way to cook the fish for optimum flavor and crunchiness, and training employees in how to prepare it. Even the bottom line didn't impress Kroc; he guessed that the Pope would change the rule about no meat on Fridays, and that actually did come to be just a few years later. Today, Catholics are only required to abstain from meat on Fridays during Lent.

Still, he knew Groen had a point; some kind of alternative sandwich was needed. Kroc thought he had the perfect idea: the Hula Burger, a fried pineapple slice topped with a slice of cheese on a hamburger bun. Now it was Groen who wasn't convinced. The two decided to release both burgers on a single Friday and see which one sold better. The Filet-O-Fish ended up winning by a landslide, selling 350 sandwiches compared to the Hula Burger's meager (to say the least) six. Kroc conceded, and the Filet-O-Fish went into production. It was officially added to McDonald's menus nationwide in 1965. Although a lot's changed since then, Reckon reports that a quarter of the sandwich's impressive yearly sales figures are still earned during Lent.

The Filet-O-Fish is now a classic McDonald's menu item. But unlike the chain's iconic burgers, the Filet-O-Fish has its own way of being prepared, and even equipment set aside specifically for making it. First, there's the fryer. McDonald's official website informs customers that the Filet-O-Fish is cooked in its own fryer. This keeps the patty from adding a seafood flavor to other menu items, and it also means that people who can't or choose not to eat meat won't have to worry. That said, the site cautions customers that when the fryers are being cleaned, it's possible that there could be cross-contamination with the oil from the chicken fryer.

The Filet-O-Fish is also the only permanent McDonald's menu item with a steamed bun. McDonald's doesn't seem to have issued a statement about why they chose a steamed bun, but Quora user Vrushank Muzumdar, who's worked in the restaurant business, thinks the steamed bun was picked because it absorbs the delicious tartar sauce better and adds more flavor to the sandwich. 

Its combination of fried fish, cheese, and a creamy sauce certainly make the Filet-O-Fish tasty, but you may be surprised that it's also somewhat healthy, at least as fast food offerings go. The Filet-O-Fish is frequently listed among the healthiest items you can order at McDonald's.

Nutritionist Lauren Manaker told Health that fish is full of nutrients like omega-3 fatty acids and protein ... although she concedes that the frying process makes the Filet-O-Fish's filet a bit less nutrient-packed than non-fried fish would be. Manaker also points out that since McDonald's lets customers customize their orders, you can ask for your Filet-O-Fish without cheese or without tartar sauce to reduce calories and sodium. Speaking of sodium, nutritionist Mia Syn told Shape that the Filet-O-Fish is one of the McDonald's menu items with the lowest amount of sodium, even if you keep the sauce and cheese.  

We don't always associate fast food with natural ingredients, but the Filet-O-Fish has been made with real fish from the start. Its creator, Lou Groen, used halibut in his prototype sandwich, but over time the fish has changed. Today, the Filet-O-Fish is made from Alaskan pollock in most locations, though some might feature different fish. For instance, at McDonald's restaurants in Australia and New Zealand, the Filet-O-Fish is made from a combination of Alaskan pollock and locally fished hoki.

Whatever fish is used in the Filet-O-Fish, it's almost certain to be sourced from a sustainable fishery.  McDonald's proudly proclaims that it was the first fast food restaurant to be certified by the Marine Stewardship Council. McDonald's has been using sustainable fish for the Filet-O-Fish since 2013 . Today, McDonald's reports that 93.8% of the fish they use in locations around the world is sustainable, and a statement on the chain's official site says they're hoping to make that 100% one day.

Look at online McDonald's menus around the world and you're pretty likely to find the classic Filet-O-Fish, a testament to its far-reaching appeal. But some McDonald's locations also offer variations on the version we all know and love, whether as permanent menu features or limited time promotional items. For instance, in some markets, including France, Belgium, Spain, and Brazil, there are two incarnations of the Filet-O-Fish, the original and the McFish, which consists of the Filet-O-Fish patty topped only with ketchup.

You'll also find a Filet-O-Fish sandwich topped with wasabi in some McDonald's restaurants in Asia, as well as in places like France. Depending on the location, the Filet-O-Fish with wasabi is either a permanent menu item or a seasonal or promotional one. Another limited-time take on the Filet-O-Fish is a version where the tartar sauce is replaced by Old Bay seasoning. You might come upon this spin on the traditional favorite at McDonald's locations in and around Maryland and Washington D.C. , where Old Bay is a cupboard essential.

Besides its delicious taste, the Filet-O-Fish is a mainstay on McDonald's menus around the world for a similar reason as why it was created in the first place: It's one of the restaurant's few offerings that just about everyone can eat. In addition to anyone whose diet doesn't allow them to eat red meat, it's also a feasible meal for followers of many religions. Besides still being a popular menu item for Catholics during Lent, the sandwich is considered acceptable to most followers of Hinduism. 

While McDonald's official U.S. website states that it "does not certify or claim any of its U.S. menu items as Halal, Kosher or meeting any other religious requirements," many Jewish and Muslim customers also consider the Filet-O-Fish okay to eat, even though strict practitioners of both religions would disagree. Still, Jewish author Jonathan Zalman (via Tablet) dubbed it "the most kosher non-kosher food at McDonald's," and Muslim writer Mariam Ansar (via Vice) calls it "A compromise made up of being Western and a practising Muslim." That said, there are some halal McDonald's locations in countries like the United Arab Emirates, and several kosher McDonald's in countries like Israel, so some customers may be enjoying the Filet-O-Fish without any qualms.

Many Chinese families in North America also have a special place in their hearts for the Filet-O-Fish. For instance, Melissa Hung shared with Shondaland how her Chinese family found fish more familiar and comforting than beef burgers when they first came to the U.S. In a touching article for the New York Times, Jane Hu echoed this sentiment, sharing how, after immigrating with her family from China to Canada as a kid, she saw the Filet-O-Fish's steamed bun and sweet and sour tastes as a reminder of home.

Not every sandwich can say it inspired a novelty item, and fewer still can say that this novelty item was a singing fish, but the Filet-O-Fish can proudly claim both accomplishments. In 2009, McDonald's released a commercial featuring a wall-mounted singing fish officially known as Frankie the Fish. Like Big Mouth Billy Bass, the original novelty toy that no doubt inspired his creation , Frankie could move and sing. But unlike any singing fish before him, Frankie sang about the Filet-O-Fish, notably the refrain, "Give me back that Filet-O-Fish, gimme that fish!" 

The song was simple, but catchy, and the commercial was weird enough to get noticed — and then go viral. As NBC 4 Washington put it at the time, "Catchy Filet-O-Fish Jingle Has Us Hooked", and they were far from the only ones. According to Chris Edwards, a creative exec who worked on the ad campaign, Frankie the Fish increased Filet-O-Fish sales by 22%. An actual singing Frankie the Fish novelty toy was created in response to the commercial's popularity. But just like most viral phenomena, the hype over Frankie has since died down, and the toys are rare today. If you're lucky, you might hook yourself one on Ebay. 

Tartar sauce is typically a mix of mayonnaise, pickles, capers, shallots and herbs. There are many variations of this recipe, including several tartar sauces that also include Worcestershire sauce. No one is exactly sure where tartar sauce originated; some have guessed Ancient Rome, although most sources attribute it to French cuisine. But one thing pretty much universally agreed on is that while tartar sauce can be used with lots of different foods, it's especially delicious on fish.

Although McDonald's didn't invent tartar sauce, their take on it is pretty popular. If you're a fan of it, you have the Filet-O-Fish to thank. The sauce was introduced as the sandwich's classic topping. In fact, one of the ratchet guns the chain uses to put their signature tartar sauce on the Filet-O-Fish sandwich is even on display at The Smithsonian. Today, depending on the rules at your local McDonald's, you may be able to order a side or extra portion of tartar sauce, with or without ordering a Filet-O-Fish. Unfortunately, if you'd love to put McDonald's tartar sauce on your food all day, every day, the chain doesn't sell the sauce in large quantities or in big bottles at the grocery store. But there are lots of copycat recipes that might help you satisfy your craving until your next trip to McDonald's.

In 1971, McDonald's released some of its famous characters into the world, and gave them a place to live. Featured in the chain's commercials, and often spun off into Happy Meal toys, TV specials, and direct-to-video movies, McDonaldland was the realm that Ronald McDonald and friends like Grimace, the Hamburglar, and Mayor McCheese called home. It was a colorful world whose landscape often included McDonald's food. One of McDonaldland's geographical features was Filet-O-Fish Lake, which was, as you might guess, filled with Filet-O-Fish sandwiches. A pirate named Captain Crook, one of many largely forgotten McDonaldland characters, would steal Filet-O-Fish from the lake, or from anyone who had fished some out. 

McDonaldland and most of its population were more or less retired by the 2000s, but some of its characters crop up from time to time in places like the restaurant's PlayPlace décor. Ronald McDonald himself is still the company mascot, and in a turn that seems at once surprising and not shocking at all to anyone who was ever creeped out by these characters, Grimace has gained new popularity among younger generations for being portrayed in pop culture as a menacing figure who poisons people with McDonald's promotional Grimace Shake. Captain Crook and Filet-O-Fish Lake, meanwhile, disappeared from McDonald's promotional material long ago and are the stuff of McDonald's legend. Or, for Filet-O-Fish fans, the stuff of dreams.