Slow Cooker French Onion Meatballs

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If you love the deep, rich flavors of French onion soup, these slow cooker French onion meatballs are about to be your new obsession! Juicy meatballs simmer in a savory broth infused with caramelized onion goodness, then get smothered in melty Gruyère cheese for the ultimate cozy bite. Whether served over mashed potatoes, tucked into a crusty baguette, or skewered as an appetizer, these meatballs are pure comfort food bliss. Just toss everything in the Crockpot and let the magic happen—no need to babysit for hours!

A bowl of meatballs in gravy with onions served over mashed potatoes, garnished with parsley, and accompanied by slices of bread.

This simple slow cooker French onion meatballs recipe combines tasty ingredients with effortless preparation. The whole family will enjoy the rich flavors in this dish.

Meatball fans might also like creamy meatball stew, skillet sweet and sour meatballs, Salisbury steak meatballs and slow cooker Swedish meatballs.

Why You’ll Love It

So easy to make: There isn’t much more to do that just add your ingredients to a slow cooker and wait, enjoying the mouthwatering aroma as it cooks.
Delicious flavors: This dish delivers bold, vibrant flavors, including meatiness from the meatballs and beef broth, classic French onion soup flavors from the condensed soup, aromatic thyme and garlic, creamy gruyere cheese, and sweet onions.
A versatile recipe: Serve French onion meatballs as an appetizer or enjoy them as a main dish with your preferred sides.

Plate of meatballs in gravy over mashed potatoes, garnished with chopped parsley. A slow cooker is visible in the background.

Crockpot French Onion Meatballs Ingredients

A complete list of ingredients and amounts can be found in the recipe card below.

Meatballs: You can use frozen meatballs or make your own.
French onion soup: Make sure you get the condensed soup (This one is always good!)
Balsamic vinegar: Adds both sweetness and tang.
Gruyere cheese: Offers creamy, nutty and slightly salty flavors.
Garlic: Fresh is always best.
Beef broth: Choose a low sodium option if you can, since the dish is already salty enough.
Fresh thyme: A classic French onion soup ingredient that adds a vibrant, aromatic touch.
Sweet onions: Use Vidalia sweet onions or your preferred type.
Cornstarch: To thicken the sauce.

Assorted ingredients for a recipe: meatballs in a bowl, sliced onions, broth in a measuring cup, canned French onion soup, shredded cheese, and small bowls of garlic, herbs, flour, and sauce.

How to Make French Onion Slow Cooker Meatballs

For more detailed instructions with weights and measurements, jump to the printable recipe card.

Make the sauce: Whisk the beef broth, French onion soup, balsamic vinegar, cornstarch, black pepper, and thyme together.
Assemble the dish: Add the frozen meatballs to your slow cooker and add the garlic and onions on top. Pour the sauce over.
Cook the dish: Cover and cook on low until done, stirring halfway through cooking.
The finishing touches: Top with shredded cheese, then cover and cook for a few minutes until the cheese melts. Serve hot, garnished with fresh thyme or parsley if liked.

Substitutions and Variations

Gluten-free option: If you want a gluten-free version, ensure your meatballs, soup and broth are free from gluten.
Gruyere cheese: Substitute something else that melts well, such as fontina, provolone, Comté, mozzarella, Swiss cheese, or a blend of 2 or more types.
French onion soup: You can substitute a package of French onion soup mix.
Meatballs: Any frozen meatballs will work, so you could use Angus beef, turkey, Italian, or even fresh or frozen homemade ground beef meatballs.
Optional add-ins: Feel free to add a splash of red wine, some Worcestershire sauce or caramelized onions (caramelized in a pan before adding).

A bowl of meatballs topped with melted cheese and garnished with parsley. Fresh parsley, a salt and pepper shaker, sliced baguette, and a blue-checked cloth are nearby.

Serving Suggestions

As an appetizer: Pair your French onion meatballs with homemade bread or crackers.
As a main dish: Enjoy the meatballs over mashed potatoes, rice or egg noodles. You could also make an iceberg wedge salad or Caesar salad to have on the side. If you want the crouton element of French onion soup, you might like to make toast, cut it into cubes and sprinkle over the soup either before adding the cheese or just before serving.
In a sandwich: Make a tasty meatball sub, using sliced meatballs and toasted crusty bread, perhaps adding some salad greens in there too!

A dish of cooked meatballs covered with melted cheese and garnished with chopped parsley, placed in a white bowl.

How to Store Crockpot French Onion Meatballs

Store: Keep leftovers in an airtight container in the refrigerator and eat within 3 to 4 days.
Freeze: You can freeze this recipe in an airtight container for up to 3 months.
Thaw: Defrost it in the refrigerator overnight.
Reheat: You can warm your meatballs back up in the microwave or in a pan on the stove.

Cheesy meatballs with onions in a slow cooker, stirred with a wooden spoon.

Top Tips

Shred your own cheese: Store-bought shredded cheese will have anti-caking agents to stop the shreds from clumping together. This can affect how well it melts though, so I recommend shredding your own.
Watch the salt levels: I recommend choosing a low sodium beef broth, as the condensed French onion soup can be salty. It’s best to add salt (only if needed) at the end of cooking.
If using fresh homemade meatballs: The cooking time might be closer to 4 to 6 hours if you’re using fresh meatballs rather than frozen (cooked) ones. To check they’re done, use a thermometer. The internal temperature should be at least 160°F.
Don’t forget to stir: Stir the dish about halfway through the cooking time, to prevent it from burning on the bottom.

A bowl of meatballs in gravy over mashed potatoes, garnished with chopped parsley. A fork is placed beside the bowl, with sliced bread and parsley on the side.

Crockpot French Onion Meatballs FAQs

Do I have to add water to dilute the condensed soup?

No, just use it as it is. The beef broth in the recipe will dilute it.

Don’t I have to caramelize the onions first?

Although traditional French onion soup is made with caramelized onions, you don’t have to caramelize them first in this recipe, but you can if you want to! Caramelizing them means cooking them in butter or oil in a skillet or pot over a low heat until they’re dark in color and very rich and sweet-tasting. Doing this would add more depth of flavor to your French onion meatballs but it’s still an optional step.

Wooden spoon holding cheesy meatballs over a slow cooker filled with saucy meatballs and melted cheese. Fresh parsley garnishes the dish.

Best Slow Cooker French Onion Meatballs Recipe

A glass bowl filled with orange-brown liquid sprinkled with black and green herbs, placed on a light gray surface.

This crockpot French onion meatballs recipe is easy to prepare and it’s so tasty. Thinly sliced onions, meatballs, gruyere cheese, beef broth, and fresh thyme are just some of the vibrant flavors in this dish. Whether you choose to serve your meatballs in small portions as an appetizer or in larger ones as a main dish, you’re surely going to love the big, bold flavors every mouthful delivers.

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Bella Bucchiotti

Bella Bucchiotti is a Canadian-based syndicated food, travel, and lifestyle writer, photographer, and creator at xoxoBella. She founded xoxoBella in 2015, where she shares her love for food, dogs, sustainability, fitness, crafts, outdoor adventures, travel, and philanthropy to encourage others to run the extra mile, try new recipes, visit unfamiliar places, and stand for a cause. Bella creates stress-free and family-friendly recipes for weeknight dinners and festive feasts.