Slow Cooker French Onion Meatballs

Try my slow cooker French onion meatballs with tender beef, caramelized onions, rich broth, and melted Gruyère for a hearty comforting dinner.

For me, a good indication that a restaurant will be good is if their French onion soup is actually delicious, so I always order that as an appetizer when I see it on the menu. These slow cooker French onion meatballs have all those rich, caramelized flavors, but turned into something way more filling and family-friendly. The moment my kids tried these meatballs covered in melted Gruyère, they were completely sold.

This recipe takes all the best parts of French onion soup and turns them into something that works as a main dish. The onions get sweet and jammy after hours in the slow cooker, while the meatballs soak up all that savory broth and stay tender. The Gruyère cheese melts into this gorgeous, stretchy layer on top... just like my favorite part when ordering the soup. 

I make this whenever I crave French onion soup but need to make something filling for dinner. I prepare everything in the slow cooker and by the time I'm done working, the onions have transformed into this sweet, caramelized base that coats every meatball. The crispy fried onions on top are my favorite touch because they add this perfect crunch that contrasts with all the tender, melty components underneath.

My husband loves how hearty and satisfying these are, especially when I serve them over mashed potatoes or egg noodles. It's one of those dinners that feels so comforting after a long day of work, and it helps that I don't have to spend hours cooking on top of everything.

Ingredients

The frozen homestyle beef meatballs are what make this dish so easy to throw together without losing any flavor. They hold up perfectly in the slow cooker and soak up all that brothy goodness without falling apart on you. The thinly sliced onions are just as important because they caramelize slowly and give you that sweet, deep flavor that makes French onion soup so good.

For the broth, I use condensed French onion soup mixed with beef broth and a packet of brown gravy mix. The gravy mix is my shortcut for thickening everything up and adding that rich, savory base without having to make a roux or anything complicated. Worcestershire sauce adds this sharp depth that balances out all the sweetness from the onions.

Shredded Gruyère cheese melts right over the top for that classic French onion flavor, and I finish it off with crispy fried onions and parsley for some crunch and freshness that cuts through all that richness.

See the recipe card for exact quantities.

Step-by-step Instructions

This slow cooker French onion meatballs recipe take all the flavors of the classic soup and turn them into a hearty, shareable dish. With tender meatballs, caramelized onions, and melted Gruyère, it’s an easy comfort food recipe made right in your slow cooker.

Prepare the Base

Place the frozen meatballs directly into the slow cooker. Add the thinly sliced onions on top, spreading them out so they cook evenly alongside the meatballs.

Mix the Sauce

In a medium mixing bowl, whisk together the condensed French onion soup, beef broth, brown gravy mix, and Worcestershire sauce until smooth. Make sure the gravy mix is fully dissolved to avoid lumps.

Combine and Cook

Pour the sauce mixture over the meatballs and onions. Stir gently so the meatballs and onions are evenly coated with the sauce. Cover the slow cooker with the lid and cook on low for 6 hours or high for 4 hours, until the onions are soft and the meatballs are hot all the way through.

Add the Cheese

Once the meatballs are done, sprinkle the shredded Gruyère cheese evenly over the top. Cover the slow cooker again and let the cheese melt for about 5 minutes.

Finish and Serve

Before serving, garnish the dish with freshly chopped parsley and a handful of crispy fried onions. Serve hot, straight from the slow cooker.

Make It Better

Turn these meatballs into subs by serving them on toasted hoagie rolls with extra melted cheese for a French onion–style sandwich. They’re also great spooned over egg noodles, mashed potatoes, rice, or even a thick slice of bread to soak up the sauce. For extra depth, add mushrooms to the slow cooker while everything cooks. If you like a little heat, stir in hot sauce or a pinch of red pepper flakes. For a lighter, low-carb option, serve the meatballs over mashed cauliflower or steamed greens.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently on the stovetop or in the microwave, adding a splash of beef broth if the sauce has thickened too much. These meatballs can also be frozen, place them in a freezer-safe container or bag for up to 2 months, then thaw overnight in the fridge before reheating.

Recipe