This slow cooker French onion meatloaf is a comforting and flavorful dish that combines sweet caramelized onions, juicy ground beef, and melted cheese for a savory twist on a classic favorite. It's rich, hearty, and perfect for a cozy dinner any night of the week.

Why You’ll Love This Recipe

I love how this recipe transforms a traditional meatloaf into something extra special. The slow-cooked sweet onions melt into the beef, infusing it with a deep, rich flavor that only gets better with time. A layer of gooey melted Swiss (or Gruyère/provolone) cheese takes the dish over the top, making it feel a little more indulgent without much extra effort. It’s all done in the slow cooker, which means I can set it and forget it while the house fills with the most irresistible aroma.

ingredients

(Here's a tip: Check out the full list of ingredients and measurements in the recipe card below.)

3–4 large sweet onions, sliced
4 tablespoons salted butter
1 tablespoon olive oil
1 teaspoon sea salt
1 teaspoon coarse black pepper
1 teaspoon granulated sugar
1 pound ground beef
1 cup Italian-herb bread crumbs
1 cup milk
1 egg
1 oz. French onion soup mix
½ cup cooking sherry
½ teaspoon Worcestershire sauce
4 oz Swiss, Gruyère, or provolone cheese
Fresh thyme sprigs (for garnish)

directions

I slice the onions and layer them on the bottom of a 6-quart slow cooker. Then I sprinkle them with salt, pepper, and sugar, and dot with butter.
In a bowl, I mix the ground beef, bread crumbs, milk, egg, and French onion soup mix, then shape it into a loaf.
I pour the cooking sherry and Worcestershire sauce over the onions, then gently place the meatloaf on top.
I cook it on HIGH for about 3 hours (or LOW for longer) until the internal temperature reaches 160°F.
I top the meatloaf with cheese and cook for an additional 20–30 minutes until it’s perfectly melted and gooey.
I garnish with fresh thyme, slice, and serve with the onions and flavorful pan juices.

Servings and timing

Servings: 6
Prep Time: 10 minutes
Cook Time: 3 hours 20–30 minutes
Total Time: 3 hours 30–40 minutes

Variations

When I want to change things up, I sometimes caramelize the onions in a skillet first for deeper flavor—it takes about 15–20 minutes. I also like swapping the Swiss cheese with Gruyère or provolone depending on what I have on hand. For a leaner version, I’ve tried using ground turkey, and it still comes out delicious, though I might reduce the cooking time slightly.

storage/reheating

I store leftovers in an airtight container in the fridge for up to 3 days. To freeze, I wrap individual slices tightly in plastic wrap and place them in a freezer-safe bag. When I’m ready to eat, I reheat in the microwave or a covered baking dish in the oven at 325°F until warmed through.

FAQs

How do I know when the meatloaf is fully cooked?

I always use a meat thermometer to check the internal temperature. Once it reaches 160°F, it’s fully cooked and safe to eat.

Can I use a different type of cheese?

Yes, I often switch between Swiss, Gruyère, or provolone. All of them melt beautifully and add a slightly different twist to the flavor.

Can I prepare this ahead of time?

Absolutely. I assemble everything the night before, keep it covered in the fridge, and start the slow cooker the next day when I’m ready to cook.

Is it possible to cook this in the oven instead?

Yes, I’ve baked it at 350°F for about 60–75 minutes in a loaf pan or on a baking sheet, but I prefer the slow cooker for the extra flavor and tenderness.

What can I serve with this meatloaf?

I like serving it with mashed potatoes, roasted veggies, or a simple green salad. The rich onions and pan juices make great toppings for sides too.

Conclusion

This slow cooker French onion meatloaf is one of those recipes I turn to when I want something hearty, easy, and full of flavor. The combination of sweet onions, tender beef, and melted cheese makes it a hit every time. It’s comfort food at its best—simple, satisfying, and sure to please.