Chicken Casserole with Spaghetti Squash

This spaghetti squash chicken casserole is one of my favorite chicken dinners! Featuring juicy chicken breast, spaghetti squash, mushrooms, tomatoes, green peppers, and lots of cheese. It’s healthy comfort food that’s low carb, gluten-free, and kid-friendly! It’s an easy meal prep idea and perfect for freezer meals, too.

low carb spaghetti squash casserole with chicken

What are casseroles?

Basically, a casserole is nothing more than a few ingredients baked together in a pan. They can be sweet or savory, eaten for breakfast, lunch or dinner. Casseroles are versatile, easy to throw together at the last minute, freeze well, and are a great way to use up leftovers lurking in the fridge.

Chances are, you have eaten a casserole at some point in your life. Some of my favorite casserole recipes are:

I love them, but apparently, there are people out there who detest casseroles. The mere mention of the word “casserole” can make them run in fear. I suppose that if I were left to choose between a mushy casserole made with cream-of-something soup or a plate of lasagna roll-ups, I might choose the lasagna.

The thing is, I’m here to prove to you casserole haters out there that casseroles are not ALL mushy and gross. There are some awesome casserole recipes in the world.

Think about this… Casseroles are essentially one-pan meal prep recipes. They freeze beautifully, and since casseroles were here long before the idea of make-ahead meals, I think that makes them uber cool!

Chicken Casserole with Spaghetti Squash

My chicken casserole is full of flavor and real food ingredients. So please don’t fear this chicken dinner recipe; it makes a quick, easy, and delicious meal.

Just open your mouth and close your eyes and you will get a healthy casserole surprise!  🙂

Tips for creating perfect casseroles

  1. The first rule of casseroles: Use enough liquid to assure that any grains and meat in the casserole don’t dry out in the oven.

I realize that some people LIKE the crusty, crunchy edges in a casserole, but not this girl. I want every bite to be juicy and moist. You can have my crispy edges, okay?

  1. The second rule of thumb: There will never be a casserole with too much cheese.

That rule may only be pertinent in Wisconsin, where fresh cheese is in abundance. Regardless, there is something wonderful about eating a forkful of a cheesy casserole, having warm cheese run in strands from the fork down onto your chin.

This low carb chicken casserole with spaghetti squash has all of the elements noted above, and it’s sure to please even the casserole haters in your family.

removing strands of spaghetti squash from the cooked squash

Is spaghetti squash good for you?

For those trying to eat healthier, rejoicing may be in order, as spaghetti squash is gluten-free, low carb, and keto friendly! In fact, spaghetti squash is also paleo and Whole30 compliant! Of all the winter squashes, spaghetti squash is my favorite.

Because it comes out of the squash in long strands, I use it as a low carb substitute for pasta when I make Shrimp Scampi

Using spaghetti squash in this low carb chicken casserole makes it easy to get extra veggies into your diet. Most kids love spaghetti squash, especially with a chicken dinner.

spoon serving a low carb chicken casserole

If you plan to make or have already made this easy chicken dinner recipe, will you please leave a comment and rate the recipe for me?

Your comments and recipe ratings help me to know how I’m doing, and it helps other readers to know how well a recipe will work for them. Thank you!

Other easy chicken dinners to make:

chicken casserole recipe notes

Sadly, because cheese isn’t allowed on the Whole30 plan, this low carb chicken casserole is not paleo or Whole30 compliant. But it IS a gluten-free casserole recipe. You can certainly make the casserole recipe without cheese, or substitute nutritional yeast for the cheese, if desired.

dish of healthy spaghetti squash casserole with chicken

Chicken Casserole with Spaghetti Squash

This spaghetti chicken casserole is a budget-friendly, healthy chicken dinner recipe. Everyone in the family will love this chicken dinner. It's a great meal prep idea for make-ahead freezer meals.
5 from 6 votes
Prep Time 10 minutes
Cook Time 35 minutes
Total Time 45 minutes
Course Dinner, Main Course
Cuisine American
Servings 6 people
Calories 218 kcal


  • 3 cups cooked spaghetti squash (1 large squash)
  • 2 Tablespoons chopped fresh parsley divided
  • ¾ cup chicken bone broth or chicken stock
  • 5 ounces tomato paste
  • 4 ounces mushrooms fresh or canned, sliced
  • ½ cup onion chopped
  • ½ cup green bell pepper chopped
  • 12.5 ounces canned diced tomatoes with liquid
  • 1 tsp dried basil
  • 1 tsp garlic salt
  • ½ tsp Italian seasoning
  • ¼ tsp black pepper
  • 1 pound boneless skinless chicken breast cut into bite-sized pieces
  • 1 cup shredded mozzarella cheese
  • ¼ cup grated parmesan cheese


  • Heat oven to 375° F.
  • Lightly coat a 2 quart (or larger) casserole dish with non-stick cooking spray.
  • Spread cooked spaghetti squash into an even layer on the bottom of the dish.
  • In a small bowl, stir together 1 tablespoon of the parsley and all
  • remaining ingredients except chicken and cheeses. Pour contents over the squash.
  • Arrange chicken pieces over the squash mixture.
  • Cover dish with aluminum foil and bake for 25 minutes, or until chicken is no longer pink.
  • Uncover and sprinkle cheeses on top.
  • Return to oven and bake uncovered for another 10 minutes, or until cheese is melted and bubbling.
  • Sprinkle remaining 1 Tablespoon parsley over casserole just before serving.


Serving: 1servingCalories: 218kcalCarbohydrates: 12gProtein: 25gFat: 7gSaturated Fat: 3gCholesterol: 66mgSodium: 947mgPotassium: 791mgFiber: 2gSugar: 6gVitamin A: 815IUVitamin C: 25.5mgCalcium: 189mgIron: 2.2mg
Tried this recipe? Mention @itsyummi or tag #itsyummirecipe!
plate of gluten-free chicken casserole with spaghetti squash


        1. I’m so happy to hear that you enjoyed the casserole, Donna. Thank you so much for your comment and for rating the recipe. Best of success with WW!

    1. Great question! Spaghetti squash has high water content, so I honestly don’t think it will freeze well. That being said, I’ve never tried. If you decide to try it, please let me know how it goes!

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