This easy slow cooker Lentil Soup recipe is hearty, filling, and so flavorful. With only 15 minutes of prep and made in the crock pot, it’s a great dinner for busy weekdays or lazy weekends. Perfect for fall, winter, and any occasion. Gluten free and dairy free.

Lentil Soup
Dried lentils are commonly overlooked and completely underrated, if you ask me. You probably have a bag in your pantry right now that’s been sitting there for ages because you don’t know what to do with it. You probably don’t even know why you bought them to begin with.
Well, dust that package off because this lentil soup recipe is begging for them! Using sweet red lentils, smoked sausage, seasonings, and finished with a bright touch of lemon, you’ll be coming back for second and third helpings.

What Are Lentils?
Lentils are legumes—like their cousins peanuts, beans, chickpeas, and soybeans. They’ve been around for centuries, prepared and included in so many dishes throughout Europe, Asia, and North Africa.
There are several different types of lentils, such as black, brown, green, red, and yellow. The black and brown variety have an earthy flavor, the green has a nutty taste, whereas the yellow and red are on the sweeter side. Red lentils also break down easily and are great for sauces and soups like this one.
Is Lentil Soup Healthy?
This soup is hearty, filling, flavorful, and yes, healthy! In addition to the vegetables and chicken broth, lentils are high in protein and fiber, low in fat, and rich in minerals, making them very nutritious. They’re also a slow burning carb, so they keep you fuller for a longer period of time.
How many calories in lentil soup? This particular recipe contains 418 calories per 1 cup serving. (You can do a 50/50 ratio of broth and water to cut back on calories, but it’s more flavorful when using all broth.)
How many carbs in lentil soup? Lentils are starchy, so the carb count for this soup is on the high side at 48 carbs per serving.
Is lentil soup keto? No. Typically, you should avoid legumes on a keto diet because they are very high in carbs. However, like split pea soup, lentils are not completely impossible thanks to the high fiber. You might be able to get away with a small serving if you’re exercising. However, that is just my opinion. I am not personally on a keto diet and not informed enough about it to give solid advice.

What’s in this Lentil Soup Recipe?
You’ll need the following ingredients for this crock pot lentil soup (Scroll down for the detailed printable.)
- Lentils – this recipe calls for dried red lentils. You could use yellow or brown, but the cooking time might be longer.
- Vegetables – carrots, onion, garlic.
- Sausage – kielbasa makes this soup more hearty, filling, and flavorful, but it can be omitted if you’re trying to keep this vegetarian.
- Liquid – low sodium chicken broth and lemon juice (vegetable broth can replace the chicken broth for a vegetarian soup.)
- Seasonings – salt, pepper, red pepper flakes, dried Italian herbs.
- Olive oil – this is used to sauté the vegetables. A little bit of butter would also be delish!
How to Make Lentil Soup
This red lentil soup is so easy to make! There are only a few steps, so get out your crock pot and let’s do this. (Scroll down for the detailed printable.)
- Saute the vegetables and season.
- Add mixture to a 6-quart crock pot, along with the lentils, broth, and kielbasa.
- Cover and cook on low.
- Stir in the herbs and lemon juice.
- Serve with some crusty bread and enjoy!
How long to cook lentil soup? This soup cooks in the crock pot for 5-6 hours on low.

Recipe Notes
- Lentil soup thickens the longer it cooks/sits, so if you decide to let it go for 7-8 hours, it will resemble oatmeal more than soup.
- This soup is thick, but if you want it even thicker, a few whizzes with an immersion blender will do the trick!
- If it seems overly thick, you can add a touch more chicken broth to thin it out.
- Dried lentils are preferred over canned for taste and texture.
- Want to make this on the stovetop instead? Simply sauté the vegetables in a pot, as directed, then add all the ingredients in instead of transferring them to a slow cooker. Place lid on and turn heat down to medium-low. Simmer for 35-40 minutes or until lentils are soft. Proceed with the recipe as written.
How to Store Leftovers
How long does lentil soup last? Cool completely before storing leftovers. This soup will keep in the fridge in an airtight container for up to 4 days. Great for lunches throughout the week!
Can you freeze lentil soup? Yep! Store in a freezer-safe airtight container for up to 2 months. Thaw in the fridge overnight and wait on the stove, adding a bit more broth to loosen it up a bit.

Watch it Being Made
What to Serve with Lentil Soup
Some type of bread to dunk in the lentil soup is a must! My favorite choices include Garlic Bread, Irish Soda Bread, Homemade Focaccia, or Easy Beer Bread.
Other Soup Recipes We Love!
I hope you love this delicious and easy recipe – be sure to give it a review below! Also don’t forget to follow Belly Full on Facebook, Instagram, Pinterest, and YouTube!

Slow Cooker Lentil Soup
Ingredients
- 2 tablespoons extra-virgin olive oil
- 3 medium carrots , peeled and diced
- 1 small sweet onion , diced
- 3 cloves garlic , minced
- dash of crushed red pepper flakes
- salt and pepper , to taste
- 2 cups dried red lentils , rinsed
- 6 cups low-sodium chicken broth
- 6 ounces kielbasa , cut into small bite-sized pieces
- 1/2 teaspoon salt
- 1/2 tablespoon dried Italian herbs
- 2 1/2 tablespoons lemon juice
Instructions
- Coat a 6-quart slow cooker with nonstick cooking spray.
- In a large sauté pan, warm the olive oil over medium-high heat. Add the carrots, onion, garlic, and red pepper flakes; sauté for 5-6 minutes. Season with a sprinkle of salt and pepper.
- Transfer vegetable mixture to the slow cooker, along with the lentils, broth, kielbasa, and salt. Stir to combine, cover, and cook on low for 5 1/2 hours.
- Stir in the herbs and lemon juice. Taste and adjust seasoning, if necessary.
- Serve on its own or with some crusty bread, if desired and enjoy!
Video
Notes
Nutrition
Other Notes

Can this be done on the stove top and for how long? Thanks
Hi Judy! Yes, instructions for cooking on the stovetop instead are included in the article under “recipe notes.” Enjoy!
Very tasty, made my own crusty bread to dunk!!!
Could I used canned lentils in place of dried? If so, how would I convert that over?
Made this vegetarian so no kielbasa, used Not Chikn bouillon, no Italian spices or lemon juice. This is husband approved and freezable. I will extend by serving over rice or add potatoes when cooking.
Simple and delicious. The kielbasa flavors the soup which become creamy.
Quick question…..so the herbs and lemon juice go in after it cooks for 5-6 hours?
Hi Jamie! Yes, if you look at the printable recipe card, they’re listed going in after the soup cooks.
This was so delicious. I added some shredded cabbage the last 10 minutes.
I made this yesterday – it was incredibly delicious. I forgot to add the lemon juice. I’m not sure if leaving that out changed the overall flavor all that much. I will definitely make this again.
Wonderful lentil soup – we all loved it. Leftovers the next day were even better!
This was GREAT!
My entire family loved this. I used hot dogs instead of sausage (don’t judge!) and my picky eaters gobbled it up!
My husband is Polish so he loves Kielbasa!!! I knew he would like this soup. Winner – will make again.
looks great! i love using the crock pot for soups!
This is a great recipe – and SO easy! Thank you!
What’s not to love? Yummy soup and a great kitchen tool!
Yummy!
I loved my immersion blender so much, I actually wore it out!
What a delicious recipe! I could almost smell the soup here sitting in front of the computer.
This soup looks delicious! I love lentil soup, especially in the winter.
I will try this soup. Thanks, Amy. My stick blender is old and reluctant, so I’d love to win a new one!
I got a new slow cooker recently and this looks so good. I’ll try it soon.
I am seriously obsessed with soups. My large sauce pan might go on strike soon! Lentil soup is one of my favorites. I believe this recipe is goin on my shopping list for next week!
Lentil Soup is an all time fav in my family!!
I love lentils and kielbosa but never thought to put them together. Loved this combination so much, delicious. It was a bit thick, which was perfect for my kids. I just loosened it in individual bowls with warm broth for myself and my husband.
i absolutely love lentil soup – thanks for posting!
This was so delicious and couldn’t be easier. I’m the only one in my family who loves bean/pea soups, but everyone ate this up. Thank you!
I’ve been craving lentil soup lately… your recipe is just in time! I guess I’ll be buying some kielbasa this week!