Chicken Spaghetti Casserole

5 from 9 votes

This easy, cheesy chicken spaghetti casserole is classic comfort food!

Course Dinner

Cuisine American

Keyword chicken spaghetti, chicken spaghetti casserole

Prep Time 30

Cook Time 45

Total Time 1 15

Servings people

Calories 528kcal

Author Blair Lonergan

16 ounces spaghetti, broken into pieces
4 cups cooked and diced or shredded chicken
½ cup diced green bell pepper
½ cup diced celery
½ cup diced onion
1 (4 ounce) jar diced pimentos, drained or 1 (10 ounce) can Rotel diced tomatoes with green chilies, drained
2 (10.5 ounce) cans condensed cream of mushroom soup
2 cups chicken broth
1 ½ cups grated cheddar cheese, divided
1 cup finely-diced or grated Velveeta cheese
Kosher salt and ground black pepper, to taste

Preheat oven to 350°F. Spray a 9 x 13-inch baking dish with cooking spray and set aside. Cook spaghetti in a large pot of salted boiling water according to package instructions for al dente (almost tender, but still with a little bite). Drain and return to the pot.
Add chicken, bell pepper, celery, onion, pimentos or Rotel, condensed soup, broth, ½ cup of the cheddar cheese and all of the Velveeta. Toss to combine; season with salt and pepper to taste.
Transfer spaghetti mixture to prepared dish. Sprinkle remaining 1 cup of cheddar cheese over top.
Bake (uncovered) for 45 minutes, or until the casserole is hot and bubbly and the cheese is melted on top.

Make Ahead: This is the ultimate prep-ahead meal to get dinner on the table quickly and easily -- even on busy nights. Assemble the casserole, wrap tightly, and store in the refrigerator for up to 2 days before baking. When ready to bake, allow the dish to sit on the counter and come to room temperature for at least 30 minutes before putting it in the oven.

How to Freeze: Freeze the chicken spaghetti before baking. Wrap tightly in plastic wrap, cover with foil, and freeze for up to 3 months. When ready to enjoy, thaw in the refrigerator overnight, allow the dish to come to room temperature on the counter for 30 minutes, and then bake according to recipe instructions.

To bake from frozen, cover the dish with foil for the first 45 minutes, and then continue baking for about 30-45 more minutes (uncovered), or until heated through.

Storage: Leftover baked chicken spaghetti will last in an airtight container in the refrigerator for 3-4 days. Reheat the casserole in a 350°F oven, covered, just until warmed through (about 20-30 minutes). You can also reheat individual portions of leftovers in the microwave for about 1 minute.