If you’re staring at a bowl of leftover mashed potatoes after your Thanksgiving feast, this cozy and creamy leftover mashed potato soup is your new favorite way to give them a second life. With just a few pantry staples and one pot, you’ll create a cozy meal that transforms leftovers into something truly crave-worthy. Plus, you get to use up any frozen vegetables of your choice—peas, corn, carrots, or whatever you have on hand!

Disclosure: This post may contain affiliate links, meaning I earn a small commission if you make a purchase through one of my links—at no extra cost to you. As always, all opinions are my own. Thanks so much for your support! See my disclosure policy for more details.

Why you’ll love it

• Fast and filling: Comes together in 25 minutes flat with just one pot—ideal for the post-holiday cooking slump.
• Ultimate comfort food: Rich, creamy, and loaded with cheesy, bacon-y goodness.
• Thanksgiving leftovers win: A delicious way to use up mashed potatoes, cheese, and even those forgotten frozen veggies in the back of the freezer.

What is mashed potato soup?

Mashed potato soup is exactly what it sounds like—a velvety soup made by whisking luscious mashed potatoes into broth. It creates a rich, creamy base without needing to make a separate roux. It’s almost like a loaded baked potato in soup form!

Is this mashed potato soup healthy?

As a registered dietitian, I love turning comfort food into meals that nourish as well as satisfy. This mashed potato soup delivers just that with a perfect combo of nutrient-packed ingredients:

• Protein from bacon and cheddar: Adds staying power so this cozy bowl keeps you full.
• Fiber from frozen vegetables: A quick and easy way to boost the nutrient content and get in your veggies.
• Bone broth base: Bone broth is rich in collagen and contains amino acids like glycine as well as minerals, which research shows may help support the gut barrier, enhance nutrient absorption, and reduce gut inflammation.

What ingredients do you need?

Here’s everything you’ll need to make leftover mashed potato soup:

• Bacon: Diced and pan-fried until crispy to sprinkle on top.
• Shallots or onion: For that sweet, caramelized flavor.
• Chicken bone broth: Adds depth and richness (you can sub veggie broth if you prefer).
• Leftover mashed potatoes: Any kind works—creamy, chunky, with garlic or cheese.
• Heavy cream: Just a splash for added creaminess.
• Cheddar cheese: Melts into the soup and makes it extra decadent.
• Frozen vegetables: Peas, carrots, corn, or a medley—whatever you have!
• Chives: For a bright, oniony finish.

How do you make leftover mashed potato soup?

Follow these simple steps to transform leftovers into soup magic:

1. Cook the bacon: In a medium or large pot, cook the diced bacon over medium heat until crispy. Transfer to a paper towel–lined plate, and leave about 1 tablespoon of the drippings in the pot.

2. Sauté the shallots/onion: Add the diced shallots or onion to the bacon fat and sauté for about 5 minutes, or until soft and translucent.

3. Add broth and mashed potatoes: Pour in the bone broth and bring it to a gentle simmer. Whisk in the leftover mashed potatoes until smooth and creamy.

4. Simmer with cream and veggies: Stir in the heavy cream and frozen vegetables. Let everything simmer together for about 2–3 minutes.

5. Serve and garnish: Ladle the soup into bowls, then top each with shredded cheddar, crispy bacon bits, and a sprinkle of fresh chives.

Customize it your way

Like all of my recipes, this mashed potato soup is completely customizable. Choose what protein, veggies, and toppings you want to use.

• Protein of your choice: You can use bacon as the recipe calls for, or swap in chopped leftover turkey, ham, turkey bacon or even crumbled sausage. For a plant-based option, try sautéed mushrooms or tempeh.
• Cheese of your choice: Sharp cheddar adds a nice bite, but you can use gouda, parmesan, gruyere, or even a dairy-free cheese to match your taste.
• Feel free to mix up the vegetables: Frozen peas, corn, and carrots are a classic combo—but feel free to toss in green beans, spinach, or diced zucchini. If you have leftover roasted veggies from Thanksgiving, chop those up and stir them in too!

Recipe tips and tricks

• Serving: Pair it with a slice of crusty sourdough or leftover dinner rolls. A small green salad also adds a nice crunch and freshness to balance the creamy soup.
• Troubleshooting: If your soup is too thick, add more broth or a splash of milk to loosen it up. If it’s too thin, stir in a bit more mashed potatoes.
• Scaling: This recipe makes 4 hearty servings, but you can easily double it if you have a bigger batch of leftovers.

Can I keep leftovers?

This soup is best fresh but you can also store any leftovers in an airtight container for up to 4 days.

Need more help with recipes for your busy schedule?

In my coaching + cooking program, I help busy people with beginner cooking knowledge become confident in the kitchen so that they can enjoy nourishing foods they love and stress less about mealtime. Click here to learn more about this virtual program led by a dietitian.

save this Leftover Mashed Potato Soup recipe on pinterest:

More Thanksgiving recipe ideas:

• Sheet Pan Green Beans with Alfredo Sausage
• Air Fryer Green Beans
• Sheet Pan Turkey Tenderloin