Easy Seafood Casserole Recipe

There's something about the smell of creamy, cheesy seafood bubbling away in the oven that just makes any evening feel special. This Easy Seafood Casserole is warm, rich, and packed with tender bites of shrimp, flaky fish, and a luscious sauce that ties it all together.

The first time I made this dish was on a whim, trying to use up a mix of frozen seafood before it expired. What I thought would be a simple dinner turned into a family favorite that now graces our table regularly. It's quick, cozy, and easy enough for a weeknight, yet impressive enough to serve to guests.

Let’s dive into why this casserole deserves a permanent spot in your dinner rotation.

Why You'll Love This Easy Seafood Casserole

Get ready to fall for a dish that's as comforting as it is simple to make. This Easy Seafood Casserole checks every box for a crowd-pleasing meal.

First of all, this recipe is shockingly easy. With just a bit of chopping and a quick mix of ingredients, your oven takes care of the rest. No fancy prep or complicated techniques—just layer, bake, and enjoy.

It’s also incredibly budget-friendly, especially when you use frozen mixed seafood. You get the indulgent flavor of a restaurant dish without the steep price tag. Perfect if you're craving seafood but don’t want to splurge.

Another huge win? It’s family-friendly. Even picky eaters tend to devour this casserole thanks to its creamy texture and mild, comforting flavor. Pair it with a side of garlic bread or a green salad, and you’ve got a balanced dinner on the table in under an hour.

Finally, this dish is versatile. You can swap in different types of seafood, adjust the level of creaminess, or add some spice if your crew likes a little heat. The base recipe is flexible enough to adapt to your tastes and pantry.

Once you see how simple and satisfying this casserole is, it’ll be a go-to in your rotation. Let’s take a closer look at the ingredients that make it shine.

Ingredients Notes

What makes this casserole so special is how a few simple ingredients come together to create something hearty and flavorful. Each element plays a role in building a creamy, savory bake that feels indulgent without the hassle.

Seafood mix is the heart of the recipe. I typically use a frozen blend of shrimp, scallops, and flaky white fish, but you can use any combination you like. Just make sure everything is fully thawed and patted dry before cooking, so the casserole doesn’t get watery.

Cream of mushroom soup adds that classic casserole creaminess with minimal effort. It blends seamlessly with the seafood and adds a subtle umami richness. If you're not a fan, cream of celery or cream of shrimp soup also works beautifully.

Mayonnaise and sour cream create a creamy, tangy base that binds everything together. This combo adds richness without overpowering the delicate seafood flavor. Don’t skip either—they’re key to the casserole’s luscious texture.

Cheddar cheese gives you that irresistible golden, melty top layer. I recommend using sharp cheddar for a punch of flavor that balances the creaminess below. A little sprinkle on top before baking makes all the difference.

You’ll also want a simple breadcrumb topping for texture. Just toss plain breadcrumbs with melted butter and a bit of seasoning. It adds a crunchy contrast to the soft, creamy center.

No fancy equipment is needed—just a 9x13-inch baking dish and a mixing bowl. If you have a seafood allergy in the house, be sure to check the labels on any canned or packaged ingredients.

How To Make This Easy Seafood Casserole

Making this seafood casserole couldn’t be easier. With just a few steps and minimal cleanup, you’ll have a comforting dish ready for dinner in no time.

Start by preheating your oven to 375°F and greasing a 9x13-inch baking dish. While the oven heats up, gently thaw your seafood if it's frozen. Drain off any excess liquid and pat it dry with paper towels. This helps prevent a soggy casserole.

In a large bowl, stir together the cream of mushroom soup, mayonnaise, sour cream, and a handful of shredded cheddar cheese. Add a few dashes of salt, pepper, and your favorite seafood seasoning (like Old Bay or paprika) to taste.

Fold in your seafood mixture and give it a gentle stir so everything is well coated in the creamy sauce. Pour the whole mixture into your prepared baking dish, spreading it evenly with a spatula.

Now it’s time for the cheesy, crunchy topping. Sprinkle the rest of your shredded cheddar over the top, followed by a mixture of breadcrumbs and melted butter. I like to finish with a little paprika for color and flavor.

Bake uncovered for about 30 to 35 minutes, or until the top is golden brown and the casserole is bubbling around the edges. If you want an extra-crispy top, you can broil it for 2-3 minutes at the end—just keep a close eye on it.

From start to finish, you’ll be looking at about 45 minutes total. Once it's out of the oven, let it rest for 5 minutes before serving. This gives the sauce a chance to set and makes it easier to scoop.

Storage Options

One of the best parts of this dish is how well it stores, making it perfect for meal prep or leftovers.

If you have leftovers, let the casserole cool completely before transferring it to an airtight container. It will keep in the refrigerator for up to 3 days. The flavors deepen overnight, making it even more delicious the next day.

To freeze, portion the cooled casserole into individual servings and store in freezer-safe containers. It will last for up to 2 months in the freezer. Thaw overnight in the fridge before reheating.

When you're ready to enjoy it again, reheat portions in the microwave on medium power to avoid overcooking the seafood. For a crispier top, pop it into a 350°F oven for 10-15 minutes instead.

Avoid reheating more than once to preserve the delicate texture of the seafood.

Variations and Substitutions

This casserole is incredibly forgiving and easy to customize based on what you have on hand—or what your taste buds are craving.

If you're not into seafood, try making this with cooked chicken or turkey. Just shred or chop it into bite-sized pieces before adding it to the creamy base.

For a lighter version, substitute the mayo and sour cream with plain Greek yogurt. It keeps things creamy while cutting back on fat and adding a little tang.

Want to sneak in some veggies? Add a layer of steamed broccoli, peas, or spinach before you add the cheese topping. They blend in beautifully and bump up the nutrition.

Not a fan of cheddar? Try grated Parmesan, mozzarella, or a blend of cheeses. Each brings a different flavor and melt factor to the dish.

If you like a bit of heat, stir in a teaspoon of hot sauce or a pinch of cayenne pepper to the creamy base. It adds a gentle kick that complements the seafood beautifully.

No matter how you mix it up, this casserole is a winner. Don’t be afraid to play around—after all, the best recipes are the ones you make your own.

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