French Onion Squash Casserole Recipe – hands down the BEST squash casserole! Even our squash haters loved this casserole. Yellow squash, onion, cream of mushroom soup, french onion dip, cheddar cheese, garlic powder, and french fried onions. It’s a symphony of textures and flavors that’ll steal the spotlight at any meal. Whether you’re hosting a holiday gathering, potluck, or simply want to elevate your family dinner, this casserole is a must-try.

scooping squash casserole from a baking dish with text overlay

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Easy Squash Casserole Recipe

This French Onion Squash Casserole is comfort food at its best. One bite and you will be begging for seconds and thirds. Tender yellow squash mingling with caramelized onions, all enveloped in the rich and creamy sauce of French onion dip and cream of mushroom soup. And let’s not forget the cheddar cheese that turns into gooey perfection as it bakes. But wait, the pièce de résistance is those crispy French fried onions on top, adding the perfect crunch to every bite. Whether it’s a family dinner, potluck, or holiday meal, this casserole is a showstopper that’ll steal the spotlight.

baking dish of squash casserole on a table

How to Make French Onion Squash Casserole

This casserole is super easy to make with only a few simple ingredients. Heat olive oil in a large skillet over medium heat. Add onion and yellow squash to the pan and cook until the vegetables are tender. Drain any excess liquid from the squash mixture in a colander.

In a large bowl, mix together cooked vegetables, cream of mushroom soup, french fried onions, cheddar cheese, garlic powder, kosher salt, and black pepper. Stir well. Spread the squash mixture into a baking dish that has been sprayed with nonstick cooking spray. Bake in a preheated oven until bubbly. Sprinkle the top of the dish with additional french fried onions and cheese. Bake until the cheese melts.

Helpful Tips & Frequently Asked Questions

This recipe uses a cup of French onion dip. You want to use sour cream based French onion dip found in the refrigerated section at the grocery store. Do not use the jarred stuff in the chip aisle.
I use yellow summer squash. Can substitute zucchini.
- I find it much easier to use a mandolin to slice to squash into thin slices, but you can cut the squash by hand.
You can use any cheese that you enjoy. Monterey Jack, Gruyere, or parmesan cheese all work great.
Feel free to add a buttery cracker topping to the casserole. Crush ritz crackers and toss them with melted butter. Sprinkle cracker crumbs over the top of the casserole before baking.
Can I make Squash Casserole ahead of time? Absolutely! You can assemble it ahead of time and refrigerate it until ready to eat.
Can I freeze Squash Casserole? Yes! Assemble the casserole and cover the baking dish with plastic wrap and aluminum foil before freezing.
- Store in the freezer for up to 3 months.
- When ready to bake, thaw completely in the refrigerator and then bake as below.
Store leftovers in an airtight container in the refrigerator.

scooping squash casserole from baking dish

What to Serve with Squash Casserole

Let’s talk about what to serve with this casserole to create a well-rounded and satisfying meal. First off, this side dish is a must for any upcoming holiday meals. This goes great with your Thanksgiving turkey or holiday ham. It pairs wonderfully with classic holiday side dishes such as roasted Brussels sprouts, green beans, and cranberry sauce.

You can’t go wrong serving this alongside some delicious grilled chicken or a juicy steak – the combination of the creamy and cheesy casserole with a protein-packed main dish is an absolute delight. To add a touch of freshness, a side salad with mixed greens, tomatoes, and a tangy vinaigrette will provide a lovely contrast to the richness of the casserole.

Looking for more ideas to serve with this casserole? Here are some popular recipes from the website:

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