Creamy Chicken Spaghetti

Creamy chicken spaghetti is one of those weeknight dinners that feels like a hug in a baking dish. This casserole brings together tender shredded chicken, sauteed bell peppers, and al dente spaghetti wrapped in a rich homemade mozzarella cream sauce – no canned soup needed, just simple ingredients and real flavor.

I keep a bag of rotisserie chicken in the fridge most weeks, and this baked chicken spaghetti casserole is one of the first places it ends up. The homemade cream sauce takes about 10 minutes to pull together, and once it coats the pasta and chicken, every bite is rich, cheesy, and satisfying. With under 10 ingredients and a prep-ahead option, this easy chicken pasta bake fits into even the busiest week without a second thought.

What You Will Need to Make This Cozy Casserole

I always recommend prepping all your ingredients before starting the sauce – it moves quickly once the butter hits the pan. Pro tip: shred your own mozzarella from a block for the best melt. Pre-shredded bags contain anti-caking powder that keeps the sauce from coming together smoothly.

• 10 oz dry spaghetti noodles
• 2 tablespoons unsalted butter
• 1 clove garlic, minced
• 1/2 green bell pepper, chopped (diced mushrooms or chopped spinach work great here too)
• 1/4 cup all-purpose flour
• 1 teaspoon Italian seasoning
• 1/4 cup heavy whipping cream
• 1/2 cup chicken broth
• 1/2 cup milk (whole milk gives the richest result, but any variety works fine)
• 1 1/2 cups shredded mozzarella cheese, divided
• Salt and pepper, to taste
• 2 cups shredded cooked chicken (rotisserie chicken is a great time-saver)
• 14 oz canned diced tomatoes (1 can), drained thoroughly

How to Make Creamy Chicken Spaghetti Step by Step

I recommend getting the pasta boiling first and prepping your vegetables while it cooks – that way everything is ready when the sauce needs it. Timing is simple, and the whole dish comes together in about 35 minutes.

Step 1: Preheat your oven to 375 degrees F. Grease a 9×13-inch baking dish and set aside. Cook spaghetti according to package directions until just al dente – do not go past this point. It will continue cooking in the oven and will become mushy if pre-cooked too long. Drain and set aside.

Step 2: In a large skillet over medium-high heat, melt the butter. Add the minced garlic and chopped bell pepper. Saute until softened and fragrant, about 5 to 7 minutes. The garlic should be golden and the pepper tender.

Step 3: Stir in the flour and Italian seasoning. Cook for 1 full minute, stirring constantly, until the mixture turns light golden. Do not skip this step – toasting the roux removes the raw flour taste and builds a deeper, nuttier flavor base.

Step 4: Pour in the heavy whipping cream, chicken broth, and milk all at once. Stir continuously and bring to a gentle boil, then reduce heat and simmer until the sauce thickens, about 3 to 4 minutes. Keep stirring – milk and cream scorch quickly at high heat. The sauce will look glossy and coat the back of a spoon when ready.

Step 5: Remove the pan from heat. Stir in 1/2 cup of the shredded mozzarella until fully melted and smooth. Season with salt and pepper to taste. The sauce will be very thick at this stage – that is correct and intentional.

Step 6: Add the cooked spaghetti, shredded chicken, and drained diced tomatoes to the skillet. Toss everything together until evenly coated in the creamy cheese sauce. Spread the mixture evenly into the prepared baking dish.

Step 7: Sprinkle the remaining 1 cup of shredded mozzarella evenly over the top.

Step 8: Bake for 15 to 20 minutes until the edges are bubbling and the cheese on top is fully melted. For a crispier, golden top, switch to broil for an additional 2 to 3 minutes – watch it closely the entire time as it browns fast.

Step 9: Serve immediately straight from the dish while hot and bubbly.

Best Sides to Serve With Creamy Chicken Spaghetti

The rich, cheesy flavors in this creamy chicken spaghetti pair best with simple sides that complement without competing. Here are the best sides for creamy chicken spaghetti:

Garlic Bread: A natural partner for scooping up extra cream sauce from the dish. The buttery crunch balances the soft, saucy casserole perfectly.

Simple Green Salad: A crisp salad with a tangy vinaigrette cuts through the richness of the casserole and keeps the meal feeling light and balanced.

Roasted Broccoli: The caramelized, slightly nutty edges of oven-roasted broccoli add great texture contrast and a nutritional boost alongside this hearty bake.

Steamed Green Beans: A quick, unfussy side that adds color and freshness to the plate. Season simply with butter and a pinch of salt.

More Comforting Pasta and Chicken Dinners to Try

If this creamy chicken spaghetti casserole hit the spot, there are plenty more satisfying pasta and chicken dinners worth bookmarking. The Best Monterey Chicken Spaghetti brings a smoky, cheesy twist to a similar baked spaghetti base, while the Creamy Cajun Chicken Spaghetti adds a bold spiced kick that works beautifully with the same shredded chicken technique.

For nights when a full casserole feels like too much, the Garlic Butter Chicken Pasta comes together in one pot with rich, buttery flavor, and the Chicken Fajita Pasta delivers smoky fajita seasoning in a creamy pasta format the whole family will request again and again.

Storing and Reheating Your Chicken Spaghetti Casserole

Leftover creamy chicken spaghetti keeps well and tastes just as satisfying the next day. Transfer fully cooled leftovers to an airtight container and refrigerate for up to 3 days.

To reheat, warm covered in a 375 degree F oven for about 15 minutes until heated through. For individual portions, microwave in 60-second intervals, stirring between each, until hot all the way through.

Pro tip – this easy chicken pasta bake is also fully freezer-friendly. To freeze before baking, line the dish with parchment paper, assemble without baking, freeze solid, then transfer the frozen block to a large freezer bag to free up the dish. Freeze for up to 3 months and thaw overnight in the refrigerator before baking as directed. To freeze after baking, cool completely, portion into freezer-safe containers, and freeze for up to 3 months.

Frequently Asked Questions About Creamy Chicken Spaghetti

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