Easy Thanksgiving Casserole with Leftovers

This cozy, layered casserole is the ultimate way to transform Thanksgiving leftovers into an entirely new meal! It’s warm, comforting, incredibly easy, and uses ingredients you already have on hand. No extra shopping. No complicated steps. Just a simple, satisfying way to stretch your Thanksgiving food and reduce waste.

If you love creative leftover recipes, and cozy casseroles, like our family does, this recipe will become a yearly tradition. We make it every year, the day after Thanksgiving!

Scroll down for the recipe card, followed by detailed step-by-step instructions (with photos). 

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Thanksgiving Casserole with Leftovers Recipe

Why You’ll Love This Thanksgiving Casserole

This recipe is intentionally simple, flexible, and forgiving — which is exactly what you want after hosting (or attending) a big holiday meal.

Here’s why readers keep coming back to this recipe:

• It uses 100% Thanksgiving leftovers
• No exact measurements required
• Ready in under an hour
• Kid-friendly and crowd-approved
• Comfort food at its best
• Easy to customize based on what you have

A Cozy Way to Reduce Food Waste After Thanksgiving

One of the biggest challenges after Thanksgiving is food waste. So much effort goes into cooking the meal, and yet leftovers often end up forgotten in the fridge.

This Thanksgiving leftover lasagna is a practical solution that:

• Combines multiple leftovers into one dish
• Makes leftovers feel exciting again
• Feeds your family for another night (or two!)

Ingredients You’ll Need

One of the best parts of this recipe is that you don’t need to measure perfectly. Think of it more as layering flavors than following strict amounts.

You’ll need:

• Leftover turkey, shredded or chopped
• Leftover stuffing
• Cranberry sauce (whole berry or jellied both work)
• Mashed potatoes
• Gravy, for serving

No noodles. No cheese required. No extra prep work. Just layers of classic Thanksgiving flavors baked together into a hearty casserole.

How to Make Thanksgiving Leftover Lasagna

This recipe comes together quickly, making it perfect for the day after Thanksgiving when no one wants to spend hours in the kitchen.

Step-by-Step Instructions for Thanksgiving Lasagna

1. Preheat your oven to 375°F (190°C).

2. Lightly grease a 9×13-inch casserole dish.

3. Spread the shredded turkey evenly across the bottom of the dish.

4. Add a layer of leftover stuffing on top of the turkey.

5. Spoon cranberry sauce evenly over the stuffing layer.

6. Gently spread the mashed potatoes over the top, covering the entire casserole.

7. Cover the dish with foil.

8. Bake for 30 minutes, then remove foil.

9. Bake uncovered for another 10–15 minutes, until heated through and lightly golden on top.

10. Let rest for 5–10 minutes, then serve with warm leftover gravy.

Tips for the Best Leftover Thanksgiving Casserole

• Warm mashed potatoes slightly before spreading to make them easier to work with.
• If your stuffing is dry, drizzle a little gravy or broth over it before layering.
• Don’t pack the layers too tightly, light layers heat more evenly.
• Let the casserole rest before cutting so layers hold together better.

Optional Add-Ins & Variations

This recipe is endlessly customizable depending on what you have leftover.

Delicious Variations to Try

• Add a layer of leftover green bean casserole
• Sprinkle shredded cheddar or mozzarella cheese on top
• Mix gravy directly into the turkey layer for extra moisture
• Add sautéed onions or mushrooms between layers
• Use sweet potatoes instead of mashed potatoes

This is one of those recipes where there’s truly no wrong way to make it.

What to Serve With Thanksgiving Leftover Casserole

This dish is hearty enough to stand alone, but if you want to round out the meal, serve it with:

• Warm leftover gravy
• Simple green salad
• Roasted vegetables
• Homemade rolls or sourdough bread

Can You Make a Thanksgiving Casserole Ahead of Time?

Yes! This is a fantastic make-ahead dish.

You can assemble the casserole up to 24 hours in advance, cover it tightly, and refrigerate until ready to bake. When baking from cold, add an extra 10 minutes to the covered bake time.

I like to have my pan ready while I shred the rest of the turkey after dinner. I get every last bit of meat off the bones and put it directly into the pan. Then I take any leftover stuffing, cranberry sauce and mashed potatoes and assemble it right then and there. This way the day after Thanksgiving all I have to do is pull the foiled pan from the fringe and bake it in the oven! ♡

How to Store & Reheat Leftovers

Store leftover lasagna in an airtight container in the refrigerator for 3–4 days.

To Reheat:

• Oven: Cover and reheat at 350°F until warmed through
• Microwave: Heat individual portions until hot

For best texture, add a little gravy before reheating to prevent dryness.

Can You Freeze Thanksgiving Casserole with Leftovers?

Yes — this recipe freezes beautifully.

To freeze:

1. Assemble the casserole in a freezer-safe dish.
2. Cover tightly with plastic wrap and foil.
3. Freeze for up to 2 months.

To bake from frozen:

• Thaw overnight in the fridge, then bake as directed
  or
• Bake from frozen at 375°F, covered, for about 60 minutes, then uncover and bake until hot.

Why This Recipe Works So Well

Thanksgiving foods are already designed to complement each other. This casserole simply layers those flavors into one dish , savory turkey, herby stuffing, cranberry sauce, and creamy mashed potatoes.

It’s comforting, and incredibly satisfying.

And best of all? It helps you enjoy Thanksgiving a little longer without feeling like you’re eating the same meal on repeat.