Creamy and loaded with bright, fresh flavors, this Easy Keto Tomato Basil Soup will quickly become a new family favorite – especially served with my Keto Cheesy Herb Muffins!!!

When I was a kid I used to love condensed tomato soup from a can, which my mom would usually serve alongside grilled cheese sandwiches made on cheap white bread with lots of butter. It was one of my favorite lunches and tasted even better when we’d just come inside from playing in the snow and were frozen to the bone. There was nothing better than having the day off from school for a snow day and trudging in and getting hit in the face with that sweet and pungent tomato soup smell at lunchtime.
Soup from a can isn’t something I’ve had in many years, but when I set out to create a tasty and easy keto tomato soup recipe, I started with the flavor and smell I remembered from my childhood in mind. Since my taste buds have gotten more discerning over the years, I wasn’t quite as enamored with the basic flavor of the tomato soup as is, so I threw in some dried basil and finished it with some pesto I had kicking around in the fridge at the end.
The addition of basil and pesto really took this already tasty keto tomato soup to the next level of “this is so good that I can’t stop eating it!”

Since we’re rounding the corner into Spring, this is a great transition soup that is still creamy and comforting, but also sports the brighter, fresher flavors that we’re all starting to crave about now. And you won’t have to stand over the stove for hours to make it, leaving you more time to enjoy the warmer (maybe) and sunnier (hopefully) days ahead.
The tasty looking muffins that you see in the photos are the Keto Cheesy Herb Muffins that I posted recently – and they are amazing. Tender and flavorful, they are the perfect accompaniment to this easy Keto Tomato Basil Soup and stand in perfectly as a keto replacement for the grilled cheese sandwiches of my childhood.

It’s my hope that this easy low carb tomato soup recipe will bring back pleasant childhood memories for you as it did for me, but even if it doesn’t, or if you haven’t been a fan of tomato soup in the past – I hope you’ll give it a try anyway and report back!
Easy Keto Tomato Basil Soup Recipe Note:
Be sure to use good quality canned tomatoes for this recipe since there aren’t a lot of other ingredients to mask the bitter or metallic flavor that you may get with low grade canned tomatoes. Homegrown, organic and/or San Marzano region tomatoes will typically give the best flavor. I use Cento brand (not getting paid for this, just really like Cento) when I can find them and I’m never disappointed – but any brand of tomatoes grown in and imported from Italy will likely yield delicious results.
That’s not to say this easy keto tomato basil soup won’t still be tasty made with U.S. tomatoes, just maybe not quite as good as it could be.
Easy Keto Tomato Basil Soup – Low Carb
- Total Time: 12 minutes
- Yield: 6 servings 1x
Description
A creamy and delicious low carb tomato soup recipe that takes just minutes to prepare! Keto, Atkins, and gluten free – this is an easy and tasty soup that you can feel great about serving to your family!
Ingredients
- 1 can (28 ounces) whole plum tomatoes (San Marzano preferred)
- 2 cups filtered water
- 1.5 teaspoons coarse kosher salt
- 1/2 teaspoon onion powder
- 1/4 teaspoon garlic powder
- 1 tablespoon butter
- 8 ounces mascarpone cheese
- 2 tablespoons granulated erythritol sweetener
- 1 teaspoon apple cider vinegar
- 1/4 teaspoon dried basil leaves
- 1/4 cup prepared basil pesto, plus more for garnish if desired
Instructions
- Combine the canned tomatoes, water, salt, onion powder and garlic powder in a medium saucepan.
- Bring to a boil over medium-high heat and then simmer for 2 minutes.
- Remove from the heat and puree with an immersion blender until smooth (or transfer to a traditional blender and blend, then return blended soup to the pan.)
- Return to the stove and add the butter and mascarpone cheese to the soup.
- Stir over low heat until melted and creamy – about 2 minutes.
- Remove from the heat and stir in the sweetener, apple cider vinegar, dried basil, and pesto.
- Serve warm.
- Store any leftovers in a covered container in the refrigerator for up to 5 days, or in the freezer for up to three months.
Notes
Net carbs per cup = 3 grams.
- Prep Time: 2 minutes
- Cook Time: 10 minutes
Nutrition
- Serving Size: 1 cup
- Calories: 258
- Fat: 23g
- Carbohydrates: 6g
- Fiber: 3g
- Protein: 4g
New to Keto and need help getting started?? Try following my 12 weeks of free keto menu plans, starting with the 3 Day Keto Kickstart and Keto FAQs!
Or if you’re already on keto but want to boost your results, try the wildly popular and effective IBIH 5 Day Keto Soup Diet and drop as much as 10 pounds!


Ally E says
I made this tonight and I genuinely feel bad that I don’t have anyone to share this with! But because I’m lonely but because no one was home for me to show off for! HOLY COW this stuff was amazing. One of my favorite dishes before keto was a nice grilled cheese and some tomato soup. When I eat this it tastes like the grilled cheese is part of the soup cravings were completely satisfied with only one cup AND I was full!
I used Hunt’s while tomatoes and u didn’t have onion powder and it tastes AMAZING!
I am a terrible terrible cook and all of your recipes I’ve tried so far we easy enough that I could make them! You truly make it so easy to eat this wonderful food.
I’m a huge fan of your Italian meatballs too (with the mozzarella and Marinara) so good.
Mellissa Sevigny says
Thanks Ally!
Ashley B says
Delicious!
Marcia says
Delicious!
Steph says
My daughter made this and it was incredibly delicious! I’m not even a fan of tomato soup, but this tomato soup is something else. I ate two bowls!
Barbara Moreda says
This soup was lovely! You have been holding out on me. :) Tomato soup is my favorite and I have missed it. I will be honest, I never tried to make it as I figured it would be impossible to get the creaminess (when I used to use canned, I would only make it with milk). I might need to buy tomatoes by the case now …
Jennifer says
I entered this recipe into My Fitness Pal and it came back with 18.6g of carbs and 3.7g of fiber (I omitted the sweetener). How did you calculate your numbers? I wasn’t surprised with this carb count since tomatoes naturally have so much sugar.
Thanks!
Mellissa Sevigny says
I calculate all of my recipes line by line manually using Calorie King and I’m confident in my numbers. The MFP database is loaded with errors and uses averages by brand so is notoriously inaccurate with carb count.
Maria says
I tried a tomato soup recipe from another site that, although perfectly edible, didn’t have a true tomato flavor. Based on that experience I didn’t have high hopes that it was possible to make keto tomato soup that really tasted like the old familiar store-bought soups. Boy was I wrong!
I loved the idea of pesto in the soup, but omitted it (and the sweetener, vinegar, and basil) because I knew my kids would balk at it. So to get the pesto flavor in, I added a smear it to my grilled cheese–yum! I haven’t found a good mascarpone where I live but I used a mix of cream cheese, sour cream, and heavy cream per online substitution suggestions and it was still delicious!
Thanks for making a favorite comfort food keto-friendly!
Mellissa Sevigny says
Glad you were able to make it work for you Maria!!!
Crys says
What pesto do you use?
Heather says
I LOVE tomato soup and since it’s chiller than usual around my area, I’d love to make it for my son (and myself!). I would probably omit the sweetner just cause it triggers my personal cravings and my gut doesn’t really like them either. Is there something I would need to omit/add if I make it without sweetner?
Love your blog, been a long time reader! <3
Mellissa Sevigny says
If you’re using really good quality tomatoes then you probably won’t miss the sweetener at all – it just helps balance out the flavors but isn’t essential to the recipe.
Heather says
Thank you so much! That really helps me :)
Julie says
You are a star! Or should I say 5 star! Your tomato soup recipe sounds wonderful. I’m going to make it. Your blog is so inspirational. Keep up the good work!
Mellissa Sevigny says
Thanks so much Julie, hope you love the soup!