This easy slow cooker lentil soup is made with simple pantry ingredients like brown or green lentils, celery, carrot and makes a wonderfully filling and hearty vegetarian dump-and-go slow cooker meal!

white bowl of crockpot lentil soup with fresh herbs and crusty bread on the side

5 star review

“Easy to make (I’m not a good cook), healthy, delicious. Thank you. Can’t wait to serve with some fresh crispy bread and a glass of wine. ”

– Kelly
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This Slow Cooker Lentil Soup is Simply Perfect!

Lentil soup is just one of those staple recipes you need in your back pocket, as it’s not only easy to throw together, made with simple pantry ingredients, and budget friendly; but also delicious, filling, and completely nourishing. Plus, it’s a vegetarian slow cooker meal that will please both meat eaters and plant lovers alike!

I’m personally a big fan of vegetarian slow cooker recipes that feed a crowd, like my top-rated, reader-favorite vegetarian chili, but in this case I’m singing the praises of a big bowl of green lentil soup. Truly, if you’ve never made homemade lentil soup, now is the time to try it! Trust me, it’s easier than you think, especially since you don’t need to cook or soak the lentils ahead of time.

In fact, since this is a simple dump and go slow cooker recipe, you just add the lentils straight to the crockpot along with the other ingredients, hit start, and you’re well on your way to a delicious, hearty meal! This crockpot lentil soup is especially easy as most of the cooking time is hands-off due to the magic of the slow cooker, making it perfect for busy weeknights or slow weekends at home.

This version is also vegan, vegetarian, and naturally gluten-free and dairy-free, so it makes a great option when feeding people with different dietary preferences. All in all, it’s just a bowl of cozy goodness and I hope you love it!

top down view of ingredients for crockpot lentil soup in a black slow cooker pot
ladle full of lentil soup dipped into a black slow cooker pot

Making the Perfectly Thick Lentil Soup (No Pre-Soaking Required!)

For the slow cooker version of this recipe I opted to skip the saute step to keep prep easy and streamlined. If you prefer the added depth of flavor, feel free to saute the onions first in a bit of olive oil and salt over medium heat. Pureeing a bit of the cooked soup at the end using an immersion blender or regular blender lends a creamy quality without any dairy, so don’t skip this step. It’s the best way to get lentil soup that’s thick but still has plenty of texture, too.

close up of a bowl of vegetarian soup with toppings and striped blue napkin

Key Ingredients & Substitution Ideas

  • Lentils: Either green or brown lentils work in this recipe.  Do not use red lentils, as they produce an entirely different consistency and result. If you’re looking for a red lentil soup recipe, try my simple, delicious Red Lentil Soup instead.
  • Baby spinach: Kale can be used in place of baby spinach. Just be sure to add a few extra minutes of cook time at the end to wilt the kale.
  • Stock: Vegetable stock or chicken stock can be used, but be sure to use vegetable stock if you want to keep this recipe vegan and vegetarian.
  • Red wine vinegar: Finishing the soup with red wine vinegar adds a much needed flavor boost after a long cooking time. If you don’t have red wine vinegar then balsamic vinegar, white wine vinegar, or lemon juice will also work.
white bowl of crockpot lentil soup with fresh herbs and crusty bread on the side
4.93 stars (56 ratings)

Easy Slow Cooker Lentil Soup

Developed and tested by A woman with long blonde hair, smiling, holds and pours a bottle of oil in a modern kitchen setting.Robyn Conley Downs
Servings: 6
Prep: 5 minutes
Cook: 4 hours
Total: 4 hours 5 minutes
This easy slow cooker lentil soup is made with simple pantry ingredients like green lentils, celery, carrot and spinach making for a hearty vegan and vegetarian meal. Plus instant pot and stovetop directions!
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Ingredients

  • 1 medium yellow onion, chopped
  • 1 cup chopped celery
  • 2 cups chopped carrot
  • 2 cloves garlic, minced or finely grated
  • 2 teaspoons kosher salt, divided
  • 1 ½ cups dry green lentils (or brown lentils), rinsed and picked over
  • 1 (15-oz) can petite-diced tomatoes
  • 6-8 cups vegetable stock, or chicken stock (if not vegetarian)
  • 1 large bay leaf, or 2 small bay leaves

To Add at the End

  • 4 cups baby spinach
  • 1 teaspoon red wine vinegar

Optional Serving Suggestions

Equipment

Instructions 

Slow Cooker Directions

  • Add the onion, celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock and bay leaf to a 6-quart slow cooker, stirring to combine. Do not add the spinach, it will be added at the end.
  • Cover and cook on high for 4-6 hours or on low for 6-8 hours, or until the veggies and lentils are soft.
  • Remove the lid, remove the bay leaf, add the vinegar, and stir to combine. Add an additional 1-2 cups of stock to thin the soup if necessary. Taste and add the remaining 1 teaspoon salt, plus additional vinegar if desired.
  • Using an immersion blender, blend for 5-10 seconds. Alternatively, carefully, remove ½ to 1 cup of cooked soup to a blender. Cover, blend on high, then add back to the soup, stirring to combine. Note: Blending for just a few seconds will add a creaminess to the soup, while leaving the texture of most of the lentils and vegetables intact.
  • Add the spinach, and stir to combine. Serve with a generous drizzle of olive oil, and any other toppings you like.

Instant Pot Directions

  • Set a 6-quart pressure cooker to saute mode for 8 minutes. Add 1 tablespoon olive oil, onion, a pinch of salt, and cook, stirring occasionally, until the onions are soft.
  • Cancel the saute function. Add the celery, carrot, garlic, 1 teaspoon salt, lentils, tomatoes, stock, and bay leaf, stirring to combine.
  • Secure the lid, select the manual setting, and set it to high pressure for 15 minutes.
  • When the pressure cooker timer is done, allow to naturally release for 15 minutes.
  • Follow remaining slow cooker steps 3-5.

Stovetop Directions

  • Heat 1 tablespoon olive oil over medium high heat in a large Dutch oven. Add the onion and a pinch of salt, stirring to combine. Cook until the onions soften, about 8 minutes, stirring occasionally.
  • Add the celery, carrot, garlic, and 1 teaspoon salt, stirring to combine. Cook for an additional 2 minutes, stirring occasionally.
  • Add the lentils, tomatoes, bay leaf, and stock, stirring to combine. Cover, bring to a boil, then reduce to a simmer.
  • Cook, covered, until the lentils are soft, about 35-45 minutes, stirring occasionally.
  • Follow remaining slow cooker steps 3-5.

Notes

  • Salt: If the final soup tastes flat or bland to you, add more salt, 1 teaspoon at a time, until the flavor seems more robust. You can also add an additional tablespoon of red wine vinegar to taste.
  • Lentils: Dried brown, green or French lentils work interchangeably here. Do not use red lentils.
  • Temperature: The heat of slow cookers can vary, as can the amount of liquid lentils absorb during the cooking process. If necessary add additional stock at the end, to achieve your desired consistency.
  • Thicken: This soup will also thicken considerably as it cools, so if you prefer it thicker, allow to cool for 30 minutes prior to serving.
  • Serving: extra virgin olive oil, freshly cracked pepper, freshly grated parmesan cheese (traditional or vegan), fresh parsley, red pepper flakes, crusty bread
Course: Soup

Nutrition Information:

Serving: 1 (of 6), Calories: 241kcal, Carbohydrates: 45g, Protein: 15g, Fat: 1g, Saturated Fat: 1g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 1g, Sodium: 776mg, Potassium: 983mg, Fiber: 18g, Sugar: 10g, Vitamin A: 9914IU, Vitamin C: 19mg, Calcium: 97mg, Iron: 5mg
Nutrition disclaimer
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