Easy Seafood Casserole Recipe

There's something deeply comforting about a bubbling seafood casserole fresh out of the oven. The creamy sauce, tender seafood, and golden topping come together in one irresistible bite that feels both indulgent and homey.

I first whipped up this easy seafood casserole on a chilly Sunday when we were craving something cozy but didn’t want to spend hours cooking. It quickly became a family favorite – not only because it's loaded with flavor, but because it's surprisingly quick to pull together with just a handful of ingredients. Whether you're hosting a casual dinner or just need a simple weeknight meal, this casserole checks all the boxes.

Let’s dive into what makes this dish such a standout.

Why You'll Love This Easy Seafood Casserole Recipe

Get ready to fall in love with a dinner that tastes like it came from your favorite coastal bistro — all without leaving your kitchen. This easy seafood casserole is the definition of fuss-free comfort food.

First off, it’s incredibly quick and convenient. You can have everything prepped and in the oven in under 20 minutes, making it a perfect choice when you need something satisfying and stress-free after a long day.

It’s also budget-friendly. Using a mix of affordable frozen seafood and pantry staples means you can enjoy a decadent-tasting dish without spending a fortune. It’s a great way to enjoy seafood on a budget.

Another reason to love it? It’s family-friendly and crowd-pleasing. Even picky eaters tend to come back for seconds when this casserole hits the table. The creamy sauce and mild seafood make it approachable for kids and adults alike.

Lastly, this dish is versatile. You can mix and match seafood, swap in different veggies, or even top it with breadcrumbs or cheese depending on what you have on hand. It’s endlessly adaptable to your tastes and pantry staples.

Now, let’s take a closer look at what goes into this comfort-packed dish.

Ingredients Notes

The magic of this easy seafood casserole lies in its use of accessible, flavorful ingredients that come together in a creamy, savory bake. Here’s a breakdown of the key players.

Seafood is, of course, the star of the show. I usually opt for a mix of shrimp, scallops, and imitation crab for this recipe. Frozen mixed seafood works beautifully — just be sure to thaw and pat it dry before using to avoid excess moisture in the casserole.

Cream of mushroom soup forms the creamy base of the sauce. It adds richness and a subtle umami flavor that complements the seafood perfectly. You can use cream of celery or cream of shrimp soup if you prefer — they all bring something delicious to the table.

Sour cream adds tang and creaminess to balance the richness of the soup. If you're out of sour cream, plain Greek yogurt makes a great substitute while still keeping the sauce nice and thick.

Frozen vegetables, like peas or mixed veggies, give the dish color, texture, and a bit of freshness. They also help bulk up the casserole without requiring additional prep work — perfect for keeping things simple and quick.

As for special equipment, you’ll just need a large mixing bowl, a 9x13-inch casserole dish, and some aluminum foil. Nothing fancy — just classic bakeware and a hot oven.

How To Make This Easy Seafood Casserole

Making this seafood casserole is a straightforward process that doesn’t require much more than some mixing, layering, and baking. Here’s how it comes together from start to finish.

Start by preheating your oven to 375°F. Lightly grease a 9x13-inch baking dish with butter or cooking spray to prevent sticking. While the oven heats, thaw your seafood and frozen vegetables if needed, and gently pat everything dry with paper towels.

In a large bowl, combine your cream of mushroom soup, sour cream, and a generous sprinkle of salt, pepper, and Old Bay seasoning. Stir until smooth and creamy. Add the seafood and vegetables to the mixture and fold everything together gently so the seafood stays intact.

Pour the mixture into your prepared baking dish, spreading it evenly. At this point, you can add a topping if you like — crushed buttery crackers, shredded cheese, or even panko breadcrumbs work beautifully. Just a light sprinkle adds a perfect golden crust after baking.

Cover the dish with foil and bake for 25 minutes. Then, remove the foil and continue baking for another 10–15 minutes, or until the top is lightly golden and the casserole is bubbling around the edges.

Once it’s out of the oven, let the casserole sit for 5 minutes before serving. This helps everything set slightly and makes it easier to scoop. From start to finish, the whole process takes about 40 minutes — quick enough for a weeknight, but comforting enough for Sunday dinner.

Storage Options

This seafood casserole stores surprisingly well, making it great for leftovers or meal prep. Allow any remaining casserole to cool completely before transferring to an airtight container.

In the fridge, it will keep for up to 3 days. Make sure to store it in a tightly sealed container to keep the seafood fresh and avoid any fridge smells mingling with the dish.

For longer storage, you can freeze it. Place cooled portions into freezer-safe containers or wrap the entire casserole dish tightly in plastic wrap and foil. It will last in the freezer for up to 2 months. Just be sure to thaw it overnight in the fridge before reheating.

When it’s time to reheat, pop individual servings in the microwave for 1-2 minutes, or cover the whole dish with foil and warm it in a 350°F oven for about 20 minutes. Add a splash of milk or broth if it looks a little dry.

Variations and Substitutions

One of the best parts about this casserole is how customizable it is. You can tweak it to fit your mood, your pantry, or your guests’ preferences without sacrificing flavor.

If you’re not a fan of seafood or want to stretch the dish further, try adding cooked pasta or rice to the base before baking. It turns the casserole into a more filling, one-dish meal — perfect for hungry crowds.

Swap in different kinds of seafood based on what’s available. Lobster chunks, cooked salmon, or even canned tuna can give the casserole a whole new personality. Just make sure to adjust seasoning to suit the protein you use.

Want to make it lighter? Use low-fat sour cream or plain Greek yogurt, and go for a low-sodium soup base. You can also increase the ratio of vegetables for a slightly healthier spin.

Craving a cheesy version? Mix shredded cheddar or parmesan into the filling and sprinkle extra on top before baking. The added richness and gooey texture make it even more decadent.

Don’t be afraid to experiment. This casserole is forgiving and open to interpretation — which means you can make it again and again without it ever feeling boring.

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