Easy Seafood Casserole Recipe

There's something about a bubbling seafood casserole fresh out of the oven that just feels like a warm hug on a chilly evening. The rich aroma of garlic, butter, and perfectly cooked seafood mingling together is enough to gather everyone around the dinner table in a hurry.

this Recipe

I first whipped up this easy seafood casserole when I was craving something indulgent but didn’t want to spend hours in the kitchen. With just a handful of ingredients and minimal prep, it quickly became one of our family's weeknight staples—equal parts comforting, creamy, and crowd-pleasing. Whether you're cooking for two or feeding a hungry group, this recipe delivers big flavor without the fuss.

Let's dive into why this seafood casserole will soon be your go-to dinner favorite.

Why You’ll Love This Easy Seafood Casserole Recipe

Get ready to discover your new favorite comfort food. This seafood casserole isn't just tasty—it checks all the boxes for a weeknight win.

First off, it's ridiculously easy to make. With a quick prep time and simple ingredients, you can have everything in the oven in less than 20 minutes. There's no need to be a seafood expert here—just a love for creamy, savory flavors.

This dish is also incredibly versatile. Whether you prefer shrimp, scallops, crab meat, or a mix of all three, the recipe adapts beautifully to whatever you have on hand or whatever's on sale at the seafood counter.

On the budget-friendly side, it uses pantry staples like breadcrumbs and cream of mushroom soup to create a luxurious-tasting meal without breaking the bank. You can even use frozen seafood, which keeps it affordable and accessible year-round.

Lastly, it's the perfect make-ahead meal. You can assemble the entire casserole earlier in the day and just pop it in the oven when you're ready to eat. It's ideal for busy weeknights or casual entertaining.

Now that you’re excited to try it, let’s take a look at the ingredients that make this casserole so special.

Ingredients Notes

What makes this easy seafood casserole shine is its balance of rich flavors and comforting textures. Each ingredient plays a specific role in bringing it all together in one creamy, golden-baked dish.

Seafood is, of course, the star of the show. A combination of shrimp, scallops, and imitation crab meat creates a satisfying variety in every bite. You can use fresh or frozen seafood here—just make sure to thaw and pat dry before using to avoid excess moisture in the casserole.

Cream of mushroom soup forms the base of the sauce, providing that creamy, savory backbone that ties everything together. If you’re not a mushroom fan, you can substitute with cream of celery or even a homemade white sauce if you’re feeling fancy.

Mayonnaise might sound unexpected, but it’s the secret to the casserole’s rich texture and slightly tangy flavor. When combined with the soup and seasonings, it helps create a sauce that coats every piece of seafood beautifully.

Lemon juice brightens the entire dish. It cuts through the richness of the sauce and brings out the natural sweetness of the seafood. A little goes a long way, so don’t skip it!

Breadcrumbs and shredded cheese form the golden, bubbly topping. I like using a mix of Parmesan and cheddar for that perfect combo of salty and melty. A light sprinkle of paprika on top adds a pop of color and a hint of warmth.

You won’t need any fancy equipment here—just a mixing bowl, a spatula, and a casserole dish. An 8x8 or 9x13-inch baking dish works perfectly, depending on how thick you want your casserole layers.

How To Make This Easy Seafood Casserole

Whipping up this easy seafood casserole is a breeze, even if you’ve never made one before. Here's how it all comes together.

Start by preheating your oven to 350°F. While the oven warms up, lightly grease your casserole dish and set it aside. This will prevent any sticking and help the edges crisp up beautifully.

In a large mixing bowl, combine the cream of mushroom soup, mayonnaise, and lemon juice. Stir in your seasonings—salt, pepper, and a dash of paprika. Once the sauce is well-mixed, gently fold in your seafood mixture, being careful not to break up the crab too much if you're using imitation pieces.

Pour the seafood and sauce mixture into the prepared baking dish, spreading it out evenly. Sprinkle your breadcrumbs over the top, followed by a generous handful of shredded cheese. I like to give it one last light dusting of paprika for color before it heads into the oven.

Bake uncovered for 30-35 minutes, or until the top is golden and bubbling and the casserole is heated through. If you want an extra crispy topping, turn on the broiler for the last 2-3 minutes—just keep an eye on it so it doesn’t burn.

Once baked, let the casserole rest for about 5 minutes before serving. This allows everything to set slightly and makes it easier to scoop out clean portions. From prep to plate, you’re looking at around 45 minutes total, making it a totally doable weeknight dinner.

Storage Options

This seafood casserole stores like a dream, making leftovers a real treat for lunch or dinner the next day.

To store, allow the casserole to cool completely. Then transfer any leftovers into an airtight container or cover the original dish tightly with foil. It will keep well in the refrigerator for up to 3 days.

If you want to freeze it, portion the casserole into freezer-safe containers and label them with the date. Frozen seafood casserole is best enjoyed within 2 months. Just be aware that the texture of the sauce might change slightly after freezing, but the flavor will still be delicious.

For reheating, pop individual portions in the microwave for 1-2 minutes, or reheat larger amounts in the oven at 325°F until warmed through. If the topping has softened, you can sprinkle on a few fresh breadcrumbs before reheating to bring back some of that crispiness.

Variations and Substitutions

One of the best parts about this seafood casserole is how easy it is to customize based on what you love or what you have on hand.

Want a gluten-free version? Swap the breadcrumbs for a gluten-free alternative and make sure your soup is certified gluten-free. You can even use crushed gluten-free crackers or cornflakes for a fun twist on the topping.

Not a fan of mayo? Try using sour cream or Greek yogurt instead. Both will give you a similar creamy texture with a slightly different flavor profile—Greek yogurt also adds a bit of protein.

For a lower-fat version, go with light mayo and reduced-fat cheese, or swap the cream soup with a homemade white sauce made from low-fat milk and flour. You can even sneak in some steamed broccoli or peas for a veggie boost.

Mix up your seafood combo by adding cooked white fish or even canned tuna or salmon in a pinch. Just be sure everything is pre-cooked or quick-cooking so the casserole bakes evenly.

Don’t be afraid to play with flavors. Add a pinch of cayenne pepper or a dash of hot sauce for a little heat, or mix in a teaspoon of Dijon mustard for added depth.

This is one of those recipes that grows with you—once you’ve made it a few times, you’ll find yourself adapting it based on mood, season, or what’s in your fridge. Happy cooking!

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