Meatball Casserole is a cozy baked dinner made with tender Italian-seasoned meatballs, marinara sauce, pasta, and plenty of melted mozzarella. Everything comes together in one casserole dish, creating a hearty meal with bubbling cheese and savory tomato sauce throughout.

This version uses refrigerated or fully cooked meatballs to keep the preparation practical while still building flavor with garlic, Italian seasoning, and Parmesan. It is an easy make-ahead dinner that works especially well for busy weeknights.

Recipe at a Glance

Prep Time: 20 minutes
Cook Time: 35 minutes
Additional Time: 10 minutes
Total Time: 1 hour 5 minutes
Yield: 1 9-by-13-inch casserole
Servings: 6 servings
Difficulty: Easy

Why You Will Love This Recipe

Undercooked pasta finishes in the oven, preventing it from becoming mushy.
Marinara coats every component, keeping the casserole moist and flavorful.
Mozzarella creates a melty topping that browns lightly while remaining stretchy underneath.
Parmesan adds savory depth, intensifying the tomato and meatball flavors.
A short rest improves serving, allowing the sauce to settle for better portioning.

What You Need Before You Start

Large pot for pasta
Large skillet or saucepan
9-by-13-inch baking dish
Colander
Large mixing bowl
Aluminum foil
Wooden spoon or spatula

Ingredients and Helpful Swaps

■ 12 ounces penne pasta — 340 g, uncooked
■ 24 ounces fully cooked Italian-style meatballs — 680 g, thawed if frozen
■ 4 cups marinara sauce — 960 mL
■ 2 garlic cloves — about 6 g, minced
■ 1 teaspoon Italian seasoning — 3 g
■ 1/2 teaspoon red pepper flakes — about 1 g, optional
■ 1 cup shredded mozzarella cheese — about 115 g
■ 1/2 cup finely grated Parmesan cheese — about 50 g, divided
■ 2 tablespoons chopped fresh parsley — about 8 g, optional
■ 1 tablespoon olive oil — 15 mL, for greasing the baking dish

How to Make meatball casserole

Prepare the oven and baking dish. Preheat the oven to 375°F (190°C). Lightly grease a 9-by-13-inch baking dish with the olive oil.
Cook the pasta. Bring a large pot of salted water to a boil. Cook the penne according to the package directions, but stop cooking about 2 minutes before the recommended time. The pasta should be firm enough to hold its shape and still have a noticeable bite. Drain well.
Warm the meatballs and sauce. Place the marinara sauce, minced garlic, Italian seasoning, and optional red pepper flakes in a large skillet or saucepan over medium heat. Stir in the meatballs and simmer for 8–10 minutes, stirring occasionally, until the meatballs are heated through and the sauce is gently bubbling.
Combine the pasta and sauce. Add the drained pasta to the sauce and meatballs. Stir gently until the pasta is evenly coated. Stir in 1/4 cup of the Parmesan, keeping the remaining 1/4 cup Parmesan for the casserole topping.
Assemble the casserole. Transfer the pasta and meatballs to the prepared baking dish. Spread everything into an even layer so the meatballs are distributed throughout rather than concentrated in one area.
Add the cheese. Sprinkle the shredded mozzarella evenly over the top, followed by the remaining 1/4 cup Parmesan. The cheese should cover most of the surface without needing to be pressed down.
Bake covered. Cover the dish tightly with aluminum foil and bake for 20 minutes. Covering the casserole helps the pasta finish cooking without allowing the cheese to brown too quickly.
Finish uncovered. Remove the foil and bake for another 10–15 minutes, until the cheese is completely melted and lightly golden and the sauce is bubbling around the edges. The meatballs should reach at least 165°F (74°C) in the center if checking with a food thermometer.
Rest and serve. Remove the casserole from the oven and let it rest for 10 minutes. Sprinkle with the optional chopped parsley just before serving. Spoon the casserole into portions, making sure each serving gets pasta, sauce, and meatballs.

Kitchen-Tested Tip

Cook the pasta slightly less than you normally would because it continues cooking in the casserole.
Use low-moisture mozzarella if you want a more evenly browned cheese topping.

Storage and Make-Ahead Tips

Store leftover casserole in an airtight container in the refrigerator for up to 4 days.
Reheat individual portions in the microwave until steaming hot, or reheat a larger portion covered in a 350°F (175°C) oven until hot throughout.
For make-ahead preparation, assemble the casserole without baking, cover tightly, and refrigerate for up to 24 hours.

Liza's Best Kitchen Tips

If using frozen fully cooked meatballs, thaw them first unless their package specifically gives instructions for cooking from frozen.
Avoid adding extra sauce directly on top of the cheese, which can interfere with browning.
Let the casserole rest before serving so the sauce thickens slightly and the portions are easier to scoop.

FAQ

Can I use homemade meatballs?

Yes. Use about 24 ounces (680 g) of fully cooked homemade meatballs.

Can I use a different pasta?

Yes. Ziti, rigatoni, rotini, or another sturdy short pasta can replace penne.

Can I make meatball casserole ahead of time?

Yes. Assemble it up to 24 hours ahead and refrigerate it covered.

Why is my casserole watery?

Excess water can come from very wet meatballs, watery marinara, or mozzarella with high moisture content. Drain the pasta thoroughly and use a thicker marinara and low-moisture mozzarella for a more cohesive casserole.

Can I freeze meatball casserole?

Yes. Freeze the assembled casserole before baking for up to 2 months.