Juicy homemade meatballs baked in tomato sauce and finished with a blanket of melted mozzarella, this Baked Meatballs Casserole is an easy, family-friendly dinner everyone will love. It’s freezer-friendly and ideal for meal prep, making weeknights and busy seasons much simpler.
This cheesy casserole delivers classic comfort without leaving you feeling heavy—low-carb, saucy, and packed with savory flavor. The recipe is straightforward and mostly hands-off once the meatballs are formed, so it’s perfect for preparing ahead or assembling quickly on a busy evening.
As the holidays approach and schedules get full, recipes like this become essential. If you make the meatballs in advance, the final assembly takes only minutes: arrange the meatballs in a buttered casserole dish, spoon on tomato sauce, top with cheese, and bake until bubbly.
Pair the casserole with simple sides such as a shaved Brussels salad, mashed sweet potatoes, mashed cauliflower, or cauliflower rice. A hands-off vegetable side like a zucchini casserole also works well with this dish.
How to Make this Baked Meatballs Casserole
Prep the oven
- Preheat the oven to 400°F. Move the rack to the middle position and butter a casserole pan. Set aside.
Make the meatballs
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Heat olive oil in a medium skillet over medium heat and sauté the onions about 5 minutes, until softened.
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In a large bowl, combine ground beef, breadcrumbs (or almond flour), grated Parmesan, chopped parsley, egg, garlic powder, onion powder, dried basil, salt and pepper. Stir in the sautéed onions until evenly distributed.
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Use a small cookie scoop or spoon to form evenly sized meatballs and place them in the prepared casserole dish.
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Bake 15–20 minutes, until cooked through. Remove from the oven and drain excess grease.
Top and finish baking
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Spoon tomato sauce evenly over the baked meatballs and sprinkle the shredded cheese on top.
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Return the casserole to the oven and bake an additional 5 minutes, or until the cheese is fully melted and bubbly.
Recipe Variations
- Mix meats: swap half the beef for spicy pork sausage, or use ground turkey or chicken for a lighter option.
- Add veggies: fold in cooked broccoli, cauliflower, mushrooms or other vegetables before the final bake—the cheese topping hides veggies nicely for picky eaters.
- Use different cheeses: if you don’t have mozzarella, try cheddar, Monterey Jack, or a blend. Shredding block cheese melts better than pre-shredded varieties.
- Low-carb breadcrumb alternatives: use almond flour in place of seasoned keto breadcrumbs if you prefer.
Make Ahead Tip
This meatball casserole is ideal for meal prep: leftovers reheat well and can be stored in airtight containers in the refrigerator for up to four days. You can also freeze the meatballs before or after baking—prepare portions for easy reheating.
Baked Meatballs Casserole
Ingredients
- ½ cup red onion chopped
- 1 tbsp olive oil
- 1 lb extra-lean ground beef*
- ¼ cup seasoned keto breadcrumbs or almond flour
- ¼ cup grated Parmesan cheese
- ¼ cup parsley finely chopped
- 1 large egg
- 1 tsp garlic powder
- 1 tsp onion powder
- ½ tsp dried basil
- Salt and fresh ground pepper to taste
- 1 cup tomato sauce
- 1 ½ cup Mozzarella cheese for topping
- 1 tsp parsley fresh, chopped
Instructions
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Preheat oven to 400°F. Adjust the oven rack to the middle position and butter a casserole pan. Set aside.
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In a medium skillet, heat olive oil over medium heat and sauté the onions for about 5 minutes until softened.
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In a large bowl, combine ground beef, breadcrumbs or almond flour, Parmesan, parsley, egg, garlic and onion powders, dried basil, salt and pepper. Stir in the sautéed onions until evenly distributed.
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Form meatballs with a small scoop and place them in the prepared casserole dish.
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Bake 15–20 minutes or until fully cooked through. Remove and drain any excess grease.
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Top with tomato sauce and shredded cheese.
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Return to the oven and bake an additional 5 minutes, until the cheese is melted and bubbly.
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Meal-Prep: Divide meatballs, preferred vegetables, and mashed cauliflower into airtight glass containers for up to 5 days in the refrigerator. Reheat in the microwave 1½–2 minutes, adjusting time to your microwave’s power.
Notes
- To store: Keep leftovers in an airtight container in the fridge for up to 4 days.
- To reheat: Reheat leftovers in the microwave or in a preheated oven until warmed through.
- To freeze: Freeze the meatballs before or after baking. Portion and thaw or reheat directly from frozen—follow safe thawing and reheating guidelines.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.