What’s Actually in McDonald’s Filet-o-Fish Sandwich?
The Filet-O-Fish holds a special place in the nostalgic hearts of many McDonald’s fans. This simple but satisfying fish sandwich has been on the menu for decades, but what’s actually inside that crispy breaded patty?
Let’s break it down.
So, It it Really Fish?
Fish, from a fast food restaurant? It seems like little crazy. Lots of people worry if the McDonald’s Filet o Fish actually contains any fish. Is this a Diner Lobster situation?
We’ll get to that. But first, let’s take a look at the strange history of this iconic McDonald’s sandwich.
A Lost Bet
Initially, McDonald’s executives were hesitant about introducing a fish-based option, primarily due to the complexities of its cooking process. Ray Kroc, the founder of McDonald’s, had envisioned an entirely different addition to the menu – the Hula Burger, a slice of grilled pineapple paired with cheese on a bun.
Confident in his creation, Kroc struck a deal with Lou Groen, the creator of the Filet-O-Fish, to see which sandwich would prevail on a given Friday.

The wager was simple: whichever sandwich sold the most would secure a permanent spot on the McDonald’s menu. Kroc, so assured of his Hula Burger’s success, even made a side bet with his first grillman, Fred Turner, that the loser would buy the winner a new suit.
The outcome was decisive. The Hula Burger sold a mere six units, while the Filet-O-Fish soared with 350 sales. This clear victory not only won Fred Turner a new suit but also cemented the Filet-O-Fish as the first addition to McDonald’s original menu in 1965, priced at just $0.29.
As the only non-hamburger option, it marked a significant diversification of McDonald’s offerings. Today, the Filet-O-Fish remains particularly popular during the Lenten season, accounting for 25 percent of its annual sales.
The Verdict
So that’s the origin of this iconic sandwich. But today, does it still contain actual fish?
Here’s the good news. Yes, the McDonald’s Filet-o-Fish sandwich does use real fish. And perhaps surprisingly, it’s actually an environmentally friendly choice.
McDonald’s uses wild-caught Alaska Pollock in their Filet-O-Fish sandwiches. This fish is a sustainable choice, certified by the Marine Stewardship Council for its well-managed fisheries. It’s caught in the Bering Sea.
I found that really surprising. I expected some kind of mystery fish. The fact that McDonald’s uses whole fish–and sustainable ones at that–surprised me.

Alaska Pollock is a mild-flavored white fish, making it a good base for the flavorful toppings. Basically, it adds fairly little flavor of its own–it’s kind of a blank canvas for the rest of the sandwich. Previously, chains would have used cod or another whitefish, but it’s too expensive today.
Pollock is a good alternative. It’s very similar to the fish used in traditional British fish and chips.
The Breading: A Crispy Delight
The satisfying crunch of the Filet-O-Fish comes from its breaded coating. This includes wheat flour, yellow corn flour, modified food starch, and a few other ingredients for flavor and texture.
Early on, it seems people needed a bit of convincing! Saying the sandwich has a “surprisingly good taste” isn’t exactly high praise.
Yes, it’s a fried sandwich! Again, think fish and chips on a bun.
The Simplicity of Toppings
The Filet-O-Fish keeps things classic with just two toppings:
- Tartar Sauce: A creamy, tangy sauce with a base of mayonnaise, relish, chopped capers, and other seasonings.
- American Cheese: A classic half-slice of processed American cheese that adds a familiar salty, melty goodness.

The Bun: Soft and Steamed
The soft, steamed bun holds everything together, providing the perfect textural balance to the crispy fish. It’s very similar to the bun used on McDonald’s burgers.
Nutrition and Beyond
The Filet-O-Fish, while a popular choice, still falls under the category of fast food. It contains a fair amount of calories (390 for a sandwich), fat, and sodium. However, it is a decent source of protein, with 16 grams. You can find the full nutritional breakdown on the McDonald’s website.
For some, the Filet-O-Fish is a source of nostalgia or a familiar comfort food. For others, it’s simply a tasty meatless option when you’re on the go. Regardless of your reasons for choosing it, now you know exactly what’s inside this McDonald’s staple.
Going Overseas
In other parts of the world–especially countries where eating beef is uncommon or forbidden–the Filet o Fish does especially well.
McDonald’s has even introduced versions with ingredients like wasabi!
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