There’s no single season for garlic mashed potato casseroles — they’re delicious year-round. Whether for a holiday dinner, a family gathering, or a simple weeknight meal, this Cheesy Garlic Mashed Potato Casserole delivers rich, comforting flavor with an irresistible garlic and cheese finish.
Our previous 3-cheese mashed potato bake was a hit, so we revisited the concept with an extra punch of garlic and plenty of melty cheese. If you love garlic in mashed potatoes, this casserole will quickly become a favorite. It’s an easy crowd-pleaser for Thanksgiving, holiday spreads, potlucks, or any time you want to impress guests with a comforting, savory side dish.
Recipe Video
Serve this casserole with a generous helping of gravy — mushroom gravy is an excellent match — or any sauce you prefer. For cheese, feel free to use your favorite melty variety: Parmesan adds depth, while pepper jack brings a spicy kick that complements the roasted garlic. We love making a big batch of this once a month; it’s that good.
Cheesy Garlic Mashed Potato Casserole
10 servings
10 mins
35 mins
45 mins
Review
Ingredients
- Butter or cooking spray
- 4 pounds (1.8 kg) potatoes (Russet or gold preferred)
- 1/2 cup (114 g) butter (1 stick)
- 6 cloves garlic, minced
- 1/2 cup (115 g) sour cream
- 3/4 cup (180 ml) milk
- 1 1/2 cups (170 g) shredded cheddar cheese, divided
- 1 1/2 cups (170 g) shredded mozzarella cheese
- Kosher salt, to taste (or garlic salt for more flavor)
- Freshly ground black pepper, to taste
- 1/2 cup (30 g) plain or panko breadcrumbs
- (Optional) Crispy fried garlic slices for garnish
- (Optional) Minced parsley for garnish
Instructions
- Preheat oven to 400°F (200°C). Lightly butter or oil a 9″ x 13″ baking dish.
- Peel potatoes and cut into 1-inch pieces. Cook in a large pot of well-salted boiling water until tender, about 10–15 minutes depending on size.
- While the potatoes cook, melt the butter in a saucepan. Add minced garlic and cook briefly until fragrant without browning. Remove from heat.
- Drain potatoes and return to the pot or a large bowl. Add sour cream, milk, and the garlic butter. Mash to your preferred texture.
- Fold in the cheeses, reserving about 1/4 cup cheddar for the topping. Season with salt and pepper. Transfer the mashed potatoes to the prepared dish and sprinkle the remaining cheddar and breadcrumbs on top.
- Bake uncovered until the topping is golden and bubbly, about 20 minutes. Add optional garnishes and serve warm. Enjoy!
Nutrition Information per Serving
You’ll also love these potato recipes and a great gravy to serve with them:
- Air Fryer Crispy Garlic Roast Potatoes
- 3-Cheese Mashed Potato Bake
- Best Potato Casserole Recipes
- Delicious Mushroom Gravy
This recipe was originally published in 2015 and updated in 2020 with new photos.
Enjoy these comforting mashed potatoes — a simple, flavorful casserole that pairs well with almost any main course and always delights a crowd.