This seafood mac and cheese is loaded with tender shrimp, sweet lump crab, and buttery lobster in a creamy three-cheese sauce, finished with golden garlic breadcrumbs. It’s the kind of bubbling casserole that makes a holiday dinner feel extra special, but it’s just as welcome for a cozy weekend meal. If you love my Creamy Cajun Seafood Boil Pasta or Creamy Boursin Mac and Cheese, this baked seafood version belongs on your table.
Sharp white cheddar, Gruyère, and Parmesan give the sauce plenty of flavor without overwhelming the seafood. A little Old Bay, Dijon, and fresh lemon bring everything together, while a short baking time keeps the center creamy beneath that crisp, buttery topping.
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Why You’ll Love This Seafood Mac and Cheese
- Seafood in every serving: A generous combination of shrimp, crab, and lobster makes this hearty enough for dinner.
- A creamy homemade cheese sauce: A simple butter-and-flour base helps the sauce stay smooth.
- Golden, buttery breadcrumbs: Garlic Parmesan panko adds just enough crunch.
- Easy to customize: Use all three types of seafood or make it with shrimp and crab.
- Perfect for entertaining: Serve it as a Christmas dinner side, a New Year’s Eve main course, or a special Sunday supper.
Ingredients for Seafood Mac and Cheese
Pasta and Seafood
- 1 pound cavatappi, elbow macaroni, or medium shells
- 1 pound large raw shrimp, peeled, deveined, and tails removed
- 1 tablespoon olive oil
- 1 teaspoon Old Bay seasoning
- 8 ounces lump crabmeat, drained and checked for shells
- 8 ounces cooked lobster meat, cut into bite-size pieces
Cheese Sauce
- 5 tablespoons unsalted butter
- 1 small shallot, finely minced
- 3 garlic cloves, minced
- ⅓ cup all-purpose flour
- 4 cups whole milk, preferably room temperature
- 1 cup heavy cream
- 1 teaspoon Dijon mustard
- 1 teaspoon Old Bay seasoning
- ½ teaspoon smoked paprika
- ¼ teaspoon freshly ground black pepper
- 12 ounces sharp white cheddar, freshly shredded
- 6 ounces Gruyère, freshly shredded
- 2 ounces Parmesan, finely grated
- 1 teaspoon finely grated lemon zest
- Salt, as needed
Breadcrumb Topping
- 1 cup panko breadcrumbs
- 3 tablespoons unsalted butter, melted
- ¼ cup finely grated Parmesan
- ¼ teaspoon garlic powder
- 1 tablespoon chopped fresh parsley, plus more for serving
The Best Seafood to Use
Shrimp: Large shrimp give you substantial bites throughout the casserole. Cut each shrimp into two or three pieces so they distribute evenly.
Crab: Refrigerated lump crabmeat adds sweet flavor and tender pieces. Drain it well and gently check for bits of shell before using.
Lobster: Cooked claw, knuckle, or tail meat all work. Claw and knuckle meat are especially convenient for folding into pasta.
Frozen seafood works well, too. Thaw it in the refrigerator, drain thoroughly, and pat dry before cooking or adding it to the sauce. Excess moisture can make the finished mac and cheese watery.
For a more affordable shrimp and crab mac and cheese, replace the lobster with another 8 ounces of shrimp or crab.
How to Make Seafood Mac and Cheese
1. Prepare the Baking Dish and Topping
Preheat the oven to 375°F. Butter a deep 9×13-inch baking dish with approximately a 4-quart capacity.
In a small bowl, combine the panko, melted butter, Parmesan, garlic powder, and parsley. Set aside.
2. Cook the Pasta
Bring a large pot of salted water to a boil. Cook the pasta about 2 minutes less than the package directions for al dente.
Drain without rinsing. The pasta will finish cooking in the cheese sauce as it bakes.
3. Cook the Shrimp
Pat the shrimp dry, cut into bite-size pieces, and toss with 1 teaspoon Old Bay.
Heat the olive oil in a large, deep skillet or Dutch oven over medium-high heat. Add the shrimp in a single layer, working in batches if necessary. Cook for approximately 2–3 minutes total, turning as needed, until just opaque throughout.
Transfer to a plate immediately.
4. Make the Cream Sauce
Reduce the heat to medium. Melt the 5 tablespoons of butter in the same pan.
Add the shallot and cook for 2–3 minutes, until softened. Stir in the garlic and cook for 30 seconds.
Sprinkle in the flour and cook, stirring constantly, for 1–2 minutes.
Gradually whisk in the milk, adding a little at a time at first to prevent lumps. Whisk in the heavy cream, Dijon, Old Bay, smoked paprika, and black pepper.
Bring to a gentle simmer and cook for 4–6 minutes, stirring frequently, until the sauce lightly coats the back of a spoon. It should still be pourable.
5. Melt in the Cheese
Remove the pan from the heat and let the bubbling settle.
Add the cheddar, Gruyère, and Parmesan a handful at a time, stirring until each addition melts before adding more. Stir in the lemon zest.
Taste the sauce before adding salt. The cheese, Old Bay, and seafood already contribute saltiness.
6. Fold Everything Together
Stir the drained pasta into the sauce. Gently fold in the shrimp, crab, and cooked lobster, keeping some of the crab pieces intact.
The mixture should look generously sauced. If it seems stiff, stir in a splash of milk before transferring it to the baking dish.
7. Add the Topping and Bake
Spoon the seafood macaroni and cheese into the prepared dish. Scatter the breadcrumb mixture evenly over the top.
Bake uncovered for 15–20 minutes, until hot in the center and bubbling around the edges.
For a deeper golden topping, broil briefly for 1–2 minutes, watching closely.
Let rest for 5 minutes, then sprinkle with additional parsley and serve.
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Tips for Creamy Baked Seafood Mac and Cheese
Shred the Cheese Yourself
Freshly shredded cheese generally melts more smoothly than packaged shredded cheese. For the best texture, grate the cheddar and Gruyère from blocks.
Keep the Sauce Loose
The pasta absorbs sauce as it bakes and rests. Before baking, the mixture should look a little saucier than you want the finished casserole to be.
Add Cheese Off the Heat
Boiling the sauce after adding the cheese can cause it to become grainy or oily. Let the residual heat melt the cheese gently.
Drain the Seafood Well
Water from thawed lobster or crab can thin the cheese sauce. Drain thoroughly and blot away excess moisture.
Bake Just Until Hot
All the seafood is cooked before assembly. The oven’s job is to bring the casserole together and crisp the topping. Baking too long can dry out the pasta and make the shrimp firm.
What Cheese Goes Best with Seafood Mac and Cheese?
A combination of sharp white cheddar and Gruyère gives this recipe a balance of familiar cheddar flavor and a smooth, nutty finish. Parmesan adds a savory edge.
For substitutions:
- Replace Gruyère with fontina for a milder sauce.
- Use Monterey Jack in place of part of the cheddar for a softer flavor.
- Use regular sharp cheddar if you prefer a golden-colored sauce.
Keep some cheddar in the mixture for that classic macaroni and cheese flavor.
Seafood Mac and Cheese Variations
Shrimp and Crab Mac and Cheese
Use 1 pound shrimp and 1 pound lump crabmeat, omitting the lobster. Follow the recipe as written.
Lobster Mac and Cheese
Replace the shrimp and crab with additional cooked lobster for a total of 2 pounds. Fold it in just before transferring the pasta to the baking dish.
Cajun Seafood Mac and Cheese
Replace the Old Bay with a low-sodium Cajun seasoning, starting with a smaller amount and adjusting to taste. Add a pinch of cayenne if you want extra heat.
Buttery Cracker Topping
Replace the panko with 1 cup coarsely crushed buttery crackers. Reduce the melted butter in the topping to 2 tablespoons.
What to Serve with Seafood Mac and Cheese
This rich seafood pasta works well as the main course with a crisp green salad, lemony asparagus, or roasted broccoli. Keep the sides simple so the shrimp, crab, and lobster stay the focus.
For a holiday dinner, serve smaller portions alongside roast beef, turkey, or a platter of roasted vegetables.
If you’re planning more seafood dinners, try my Creamy Cajun Shrimp Tortellini for another comforting pasta with shrimp and a creamy garlic Parmesan sauce.
Creamy Baked Seafood Mac and Cheese
Creamy baked seafood mac and cheese loaded with shrimp, lump crab, and lobster in a rich white cheddar, Gruyère, and Parmesan sauce. Finished with buttery garlic breadcrumbs, this comforting seafood casserole makes a special dinner or holiday side dish.
- Prep Time: 25 minutes
- Cook Time: 35 minutes
- Total Time: 1 hour
- Yield: 8–10 servings 1x
- Category: Dinner, Side Dish
- Method: BAKED, STOVETOP
- Cuisine: American, Holiday Recipes
Ingredients
For the Pasta and Seafood:
- 1 pound elbow macaroni, cavatappi, or medium shells
- 1 pound large raw shrimp, peeled, deveined, and tails removed
- 1 tablespoon olive oil
- 1 teaspoon Old Bay seasoning
- 8 ounces cooked lump crabmeat, drained and checked for shells
- 8 ounces cooked lobster meat, cut into bite-size pieces
For the Cheese Sauce:
- 5 tablespoons unsalted butter
- 1 small shallot, finely minced
- 3 garlic cloves, minced
- ⅓ cup all-purpose flour
- 4 cups whole milk, preferably room temperature
- 1 cup heavy cream
- 1 teaspoon Dijon mustard
- 1 teaspoon Old Bay seasoning
- ½ teaspoon smoked paprika
- ¼ teaspoon freshly ground black pepper
- 12 ounces sharp white cheddar cheese, freshly shredded
- 6 ounces Gruyère cheese, freshly shredded
- 2 ounces Parmesan cheese, finely grated
- 1 teaspoon finely grated lemon zest
- Salt, as needed
For the Breadcrumb Topping:
- 1 cup panko breadcrumbs
- 3 tablespoons unsalted butter, melted
- ¼ cup finely grated Parmesan cheese
- ¼ teaspoon garlic powder
- 1 tablespoon chopped fresh parsley, plus more for serving
Instructions
- Preheat the oven to 375°F. Butter a deep 9×13-inch baking dish with approximately a 4-quart capacity.
- In a small bowl, combine the panko, melted butter, ¼ cup Parmesan, garlic powder, and parsley. Set aside.
- Bring a large pot of salted water to a boil. Cook the pasta 2 minutes less than the package directions for al dente. Drain without rinsing.
- Pat the shrimp dry and cut into bite-size pieces. Toss with 1 teaspoon Old Bay. Heat the olive oil in a large Dutch oven or deep skillet over medium-high heat. Cook the shrimp in a single layer, working in batches if needed, for approximately 2–3 minutes total, turning as necessary, until just opaque throughout. Transfer to a plate.
- Reduce the heat to medium. Melt 5 tablespoons butter in the same pan. Add the shallot and cook for 2–3 minutes, until softened. Add the garlic and cook for 30 seconds.
- Stir in the flour and cook for 1–2 minutes, stirring constantly. Gradually whisk in the milk, adding a little at a time at first to prevent lumps. Whisk in the heavy cream, Dijon, remaining 1 teaspoon Old Bay, smoked paprika, and black pepper.
- Bring to a gentle simmer. Cook for 4–6 minutes, stirring frequently, until slightly thickened but still pourable.
- Remove from the heat and let the bubbling settle. Stir in the white cheddar, Gruyère, and 2 ounces Parmesan a handful at a time until smooth. Stir in the lemon zest. Taste and add salt only if needed.
- Stir the drained pasta into the cheese sauce. Gently fold in the cooked shrimp, crab, and lobster. Keep some crab pieces intact. If the mixture seems thick, add a splash of milk; it should look generously sauced.
- Transfer to the prepared baking dish. Sprinkle evenly with the breadcrumb topping.
- Bake uncovered for 15–20 minutes, until hot in the center and bubbling around the edges. If desired, broil for 1–2 minutes to brown the topping, watching closely.
- Let rest for 5 minutes. Garnish with additional parsley and serve warm.
Notes
- Freshly shredded cheese: Grate the cheddar and Gruyère from blocks for a smoother sauce. Add the cheese off the heat and avoid boiling after it melts.
- Seafood preparation: Thaw frozen seafood in the refrigerator, drain thoroughly, and pat dry. The crab and lobster should already be cooked before adding them.
- Using precooked shrimp: Skip the shrimp-cooking step. Fold thawed, drained cooked shrimp into the pasta with the crab and lobster.
- Without lobster: Replace the lobster with an additional 8 ounces of shrimp or cooked crabmeat. Cook any additional raw shrimp as directed.
- Keep it creamy: Undercook the pasta slightly and bake only until hot. The pasta continues absorbing sauce during baking and resting.
- Make ahead: Assemble up to 1 day ahead using promptly cooled components. Cover and refrigerate, keeping the breadcrumb topping separate. Bake covered at 375°F for 25–30 minutes, then uncover, add the topping, and bake approximately 15 minutes more, until the center reaches 165°F.
- Storage: Refrigerate leftovers within 2 hours in an airtight container for up to 3–4 days. Reheat with a splash of milk until the center reaches 165°F.
Can You Make Seafood Mac and Cheese Ahead?
For the best texture, prepare the components ahead and assemble close to baking.
Shred the cheeses, mix the breadcrumb topping, and prepare the seafood the day before. Keep everything covered and refrigerated, storing the breadcrumbs separately.
You can also assemble the entire casserole up to 1 day ahead. Cool the components promptly before combining and refrigerating, and leave off the topping until baking.
Bake the refrigerated casserole covered at 375°F for about 25–30 minutes. Uncover, add the breadcrumbs, and continue baking for approximately 15 minutes, or until the center reaches 165°F. A refrigerated casserole needs longer than one assembled while warm, and the pasta will absorb more sauce.
How to Store and Reheat Leftovers
Refrigerate leftovers in an airtight container within 2 hours and use within 3–4 days.
To reheat individual portions, add a small splash of milk, cover loosely, and microwave in short intervals, stirring gently when possible.
For larger portions, place in a baking dish, add a little milk around the edges, cover, and warm at 325°F until the center reaches 165°F.
Freezing is possible, but the sauce may separate and the seafood can become firmer after thawing and reheating. This recipe has its best texture freshly baked.
Frequently Asked Questions
Can I use frozen seafood?
Yes. Thaw it completely in the refrigerator, drain well, and pat dry. Cook raw shrimp before adding it to the pasta. The crab and lobster in this recipe should already be cooked.
Can I use precooked shrimp?
Yes. Skip the shrimp-cooking step and gently fold the thawed, drained shrimp into the pasta with the crab and lobster. Avoid extra cooking before assembly.
Do I need eggs in seafood mac and cheese?
No. The butter-and-flour base thickens the sauce, and the melted cheese gives it body. This version has a creamy, spoonable center.
Why did my cheese sauce turn grainy?
High heat is a common cause. Remove the sauce from the burner before adding the cheese, stir it in gradually, and avoid bringing the finished cheese sauce to a boil.
Why is my baked mac and cheese dry?
Overbaking, too little sauce, or fully cooking the pasta before baking can leave it dry. Undercook the pasta slightly, keep the sauce generous, and take the casserole out once it is hot and bubbling.
Can I leave out the lobster?
Absolutely. Replace it with an equal weight of shrimp or crab so the casserole still has plenty of seafood throughout.
Creamy, buttery, and finished with a golden crunch, this baked seafood mac and cheese makes a generous centerpiece for a special dinner. For another seafood pasta night, save my Creamy Cajun Seafood Boil Pasta alongside this recipe.
Final Thoughts
This creamy baked seafood mac and cheese brings a little something special to the table with sweet crab, tender shrimp, buttery lobster, and a golden breadcrumb topping. Serve it for a holiday gathering or make it the centerpiece of a cozy dinner with a simple salad on the side.
If you love creamy seafood dinners, try my Creamy Cajun Shrimp Tortellini or Creamy Cajun Seafood Boil Pasta next. And if you make this seafood mac and cheese, leave a star rating and comment below—I’d love to hear how you served it!
