Easy Spaghetti Meatballs Casserole

This baked spaghetti and meatballs casserole recipe is brimming with mozzarella and parmesan cheese, al dente spaghetti, Italian seasoning, marinara sauce, and meatballs. It's the classic recipe we all love, but with a perfectly convenient twist.

Spaghetti and Meatballs Overview

Prep for this dish only takes about 20 minutes. First, thaw your meatballs, cook pasta, then add cheese, meatballs, seasonings, and sauce, then bake. Add more cheese, bake again and you have a delicious, hearty bowl of comfort ready to serve.

Baked spaghetti and meatballs casserole is the perfect meal prep dinner easily stored in the freezer. I love having a few dishes like this frozen ahead of time for busy weeknights.

I love easy ways to change up spaghetti, from this one-pot spaghetti (everything including noodles cooked together) to my healthy vegetable spaghetti, and this spaghetti squash bolognese.

Baked Spaghetti and Meatballs Video

Watch my easy tutorial video to see just how easy making baked spaghetti with meatballs really is.

Recipe Ingredients

• 14 oz spaghetti pasta
• 24 oz marinara sauce
• 15 thawed meatballs - or as many as you'd like
• 2 cups shredded mozzarella cheese - divided
• 1 cup grated parmesan cheese - divided
• ½ yellow onion - chopped
• 4 cloves garlic - minced
• 2 Tbsp Italian seasoning
• 2 Tbsp olive oil
• ½ tsp salt
• ¼ tsp ground black pepper

How To Make Spaghetti and Meatballs Casserole

Full ingredients and instructions are also in the recipe card at the bottom of this blog post.

STEP 1: Preheat oven to 375°F. Spray a casserole dish with cooking spray. Set aside.

STEP 2: Thaw 15 meatballs overnight in the fridge if possible. Thawed meatballs will cook much faster.

STEP 3: Cook 14 oz spaghetti pasta in a large pot of boiling water, and cook according to the package instructions. Drain the spaghetti through a strainer.

STEP 4: Add the spaghetti to a large bowl along with 2 Tbsp olive oil, half the shredded mozzarella cheese (1 cup), and half the grated parmesan (½ cup) then mix.

STEP 5: Add the spaghetti to the casserole dish and spread it into an even layer. Top with thawed meatballs.

STEP 6: In a separate bowl, combine 24 oz marinara sauce, ½ yellow onion chopped, 4 minced garlic cloves, 2 Tbsp Italian seasoning, ½ tsp salt, and ¼ tsp ground black pepper.

STEP 7: Pour the marinara mixture over the spaghetti and meatballs. Spread it evenly using a spatula. Cover with foil and bake for 20 minutes.

STEP 8: Remove from the oven and sprinkle the last half of grated parmesan cheese (½ cup) and shredded mozzarella cheese (1 cup). Bake for 15 minutes, until the cheese has melted.

How To Store Leftovers

• Refrigerate – You can store leftovers in the fridge for up to 3 days in a sealed container.
• Freezer – Bake this spaghetti and meatballs casserole ahead of time. Let it cool completely at room temperature, then cover it tightly with plastic wrap or a lid. This can be stored for up to 3 months in the freezer for a future meal.
• Reheat – Preheat the oven to 350°F and bake until the cheese has melted and the casserole is warmed through. Or microwave leftovers in serving-size portions for 1-2 minutes.