This Keto Tuna Casserole Recipe (0g Carbs) is a great keto, low-carb, low-cal meal that can be made in almost no time. It’s also very easy to make and it’s loaded with a ton of healthy fats and veggies. This recipe would be a great addition to any meal plan. It’s also a great way to use up any leftover tuna.

It’s been a while since I’ve had tuna, and I could really use a nice tuna casserole. However, I’ve become a little leery of canned tuna because of all the mercury and other nasties that are embedded into the can. I’ve been reading about the benefits of eating fish, and have found that there’s actually a new breed of tuna that has been farmed in a way that eliminates the mercury. I bet you’re wondering what this could have to do with a tuna casserole. Well, this one goes by the name of “Keto Tuna”.

This is my Keto tuna casserole recipe! It’s a twist on the traditional tuna casserole, but the carb content is less that 0g! It’s also lower in calories than the original.

When you’re short on time, this keto tuna casserole is the perfect rich, creamy, and hearty comfort food. It’s quick and easy to make, and it just calls for a few things you probably already have on hand.

Freshly made tuna casserole with pork rinds, celery, and carrots on a black plate.

Tuna’s Advantages

Tuna, like most fish, has a high omega-3 content (1). Omega 6 fatty acids, found in items like plant oils, are abundant in the typical American diet and can promote inflammation. A diet high in omega 3 fatty acids can assist to balance out some of the omega 6 fatty acids and lessen overall inflammation.

Choosing a Tuna

It’s fantastic to include tuna in our diet, but which tuna should you choose? Because there are so many tunas on the market, we narrowed it down to the best canned tuna to buy.

Is it better to pack in water or oil?

To begin, all tuna should be packed in water, regardless of the type. Only tuna wrapped in olive oil is an exception. Most canned tuna, on the other hand, is packed in cottonseed, sunflower, or soybean oil. These oils are heavy in omega 6 fatty acids, which nullify all of the benefits of consuming fish.

Chunk Light or Albacore?

Tuna is a large fish, thus it consumes more mercury over its lifetime. You should buy chunk light or skipjack tuna if you can find them because they are a smaller tuna species (2). If you don’t eat tuna regularly, albacore is generally alright, but if you’re attempting to limit your heavy metal exposure, it’s something to think about.

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Low-Carb Tuna Casserole with Noodles

This keto tuna casserole is loaded with cheese and taste, but it foregoes the noodles to keep carbs low. This recipe has no net carbs, making it excellent for a keto diet, however it does allow for a keto noodle alternative if needed. Zucchini noodles or black bean noodles, both of which have 8 net carbohydrates per 2oz serving size, are two of our favorites. You won’t be able to tell they’re made with beans once they’ve been smothered in tuna and cheese!

Tuna casserole being served with a black metal spoon

Tuna Casserole on a Keto Diet Instructions

Check out our casserole suggestions if you’re having trouble following our recipes or just want to know how to improve this tuna casserole.

Tuna should be drained.

Draining the tuna meat is by far the most important step for any tuna dish. If you add too much water or oil, the recipe will become runny and lose its creamy cheese basis. While the recipe only takes 20 minutes in total, you may find that it takes longer to bake off all of the excess water.

Tuna can be used in place of canned or pulled chicken.

This is a high-protein recipe with 15 grams of protein and 14 grams of fat. If you don’t have canned tuna or don’t like canned tuna, canned chicken is the next best thing. The entire cooking time will remain the same at 20 minutes, but your dish will have a more delectable cheese and chicken flavor. This is also an excellent alternative for picky youngsters, because if you blend half chicken and half tuna, they won’t be able to tell the difference!

Just in Time for the Lenten Season

Lent 2021 is quickly approaching, and fish Fridays will be here before you know it! If you can’t eat regular meat, it doesn’t mean you can’t enjoy low-carb keto dishes. On Fridays, this gluten-free keto tuna casserole will be a winner. It’s so delicious that you won’t even notice you’re not eating meat!

Recipes for Keto Seafood

There are a plethora of low carb keto fish recipes available. Here are a few of our favorites:

Fresh marinated tuna atop greens and cabbage in an Ahi Tuna Poke Bowl. Sauce, avocado, and sesame seeds are served on top. This low-carb tuna recipe will make you fall in love with poke.

Keto Fish Curry– Fresh salmon served in a delicious and creamy dairy-free coconut sauce. To make a keto-friendly supper, top zucchini noodles or cauliflower rice with it.

Another low carb baking dish recipe is Creamy Shrimp Scampi. In less than 20 minutes, you can make delicious fish scampi by tossing a few ingredients together.

We have the perfect dish for you, whether you are avoiding meat on Fridays, living a pescatarian lifestyle, or simply attempting to increase your seafood consumption. To locate your ideal seafood dish, look through all of the recipes on our blog.

Tuna Casserole on a Keto Diet: How to Make It

This low-carb tuna casserole is a reimagining of a childhood favorite. We took out the carbs and replaced them with healthy fats to create a nutrient-dense protein source. This keto tuna casserole can be made in a variety of ways and with a variety of substitutes, but the basic version is by far our favorite.


Because everyone knows tuna casserole is one of those last-minute, throw-together recipes we constantly regret not preparing enough of, this recipe is designed to be very simple. A large mixing bowl and a small casserole dish are all you’ll need.


Part of what makes comfort food so appealing is the ability to prepare it whenever you want, using whatever ingredients you have on hand. A hearty dinner, a rich basis, and a simple yet tasty concept are all required to make truly good comfort food.

All the ingredients to make tuna casserole in glass and ceramic bowls

The Base

Two 5 oz cans of tuna are required for the base of this hearty keto tuna casserole. It’s critical that you drain all of the water from your tuna. If there is too much water in a meal, it will be watery and soupy instead than rich and creamy. You’ll need mayo, shredded cheese (we used cheddar, but feel free to use a mix of your favorites), salt/pepper, and dijon mustard to form the creamy component. You can substitute yellow mustard if you don’t have dijon, but the flavor of dijon mustard is significantly superior.

You’ll also require your preferred vegetables. We used diced onion and celery, but you may use a variety of vegetables. Some folks like frozen peas, however we didn’t think the high net carb amount per serving size (14g) was worth it. Green beans, broccoli, or cauliflower rice are good alternatives.

The Finishing Touch

Finally, you’ll need a low-carb, healthful topping. For a gluten-free keto “bread crumb,” we used crushed pig rinds. This was combined with melted grass-fed butter and parmesan cheese.

How to Make Tuna Casserole on a Keto Diet

Now it’s time to assemble your delicious keto tuna casserole! This recipe has 0 grams of net carbs per serving, making it the ideal way to eat healthy after you’ve used up all of your carbs for the day. Alternatively, you might keep them for our keto chocolate cup cake.

Preheat the oven to 375 degrees Fahrenheit. In a large mixing basin, combine all of the low carb casserole ingredients. Before adding the tuna, make sure it has been thoroughly drained. Break up the fish into little pieces to avoid large clumps and to allow the mayo to coat everything.

Pork rinds, butter, and cheese lined up to be mixed together.

Place the tuna mixture in a casserole dish that has been greased. Combine all of the topping ingredients after the mixture has been placed in your dish. Top your tuna casserole with the topping, and if desired, more parmesan cheese.

Tuna Casserole being topped with the crushed pork rinds

Bake for 13-18 minutes, or until the dish is thoroughly heated and the topping is browned. Serve with fresh sliced vegetables or pig rinds and a green onion garnish!

Cheesy tuna casserole on a black plate in front of a white casserole dish with leftovers.

Keto Casserole Storage & Freezing

This low-carb tuna casserole is a quick and easy meal that can be prepared ahead of time. Make a keto tuna casserole ahead of time and freeze it for a weeknight meal.


This tuna casserole can keep for 4-5 days in an airtight jar in the refrigerator. Fish spoils faster than other meats, thus we don’t recommend keeping it in the fridge for more than 5 days.


Prepare this tuna casserole as usual and then freeze it for a quick meal. You can do this by freezing it in an airtight container or a plastic-wrapped and then aluminum-wrapped baking dish.

Allow the casserole to thaw in the fridge for 24 hours before reheating. Remove all plastic wrap and bake for 20-30 minutes at 350°F in an oven-safe dish. Before serving, make sure the center is heated.


Can I Use Fresh Tuna Steaks? – While fresh tuna steaks are excellent, the tuna should be cooked before being added to the dish. It’s preferable if the tuna is flaky and blends well with the sauce. If you wish to use fresh tuna, you’ll have to cook it first before flaking it. It’s just easier for us to use canned tuna that has already been cooked.

What Keto Veggies Should I Include? – If you want to add more keto veggie options to this meal, we’ve got you covered. Peas are included in the traditional tuna casserole, but one cup comprises 14 net carbohydrates and 8 grams of sugar per serving. Instead, consider:

  • Riced cauliflower adds weight to the dish and is simple to include. Just make sure the cauliflower rice isn’t too soggy by cooking it first. If there is too much water in the dish, it will become runny.
  • Broccoli florets- Broccoli florets absorb oil and sauce well, making them a great low-carb option.
  • Zucchini Noodles- As we mentioned above in the noodles section, zucchini is a high-fiber component to this casserole that gives it a tuna noodle feel.

What are the Carbs in Keto Tuna Casserole? – Keto tuna casserole has 0 grams of net carbs and 14 grams of fat! There are 1 gram of carbs and 1 gram of fiber, for a total of 0 net carbs and fiber.

How to Make a Creamier Keto Tuna Casserole – Our keto tuna casserole recipe is rich and delicious, but if you like something creamier, we have a recipe for you. Before baking, stir in half a block of cream cheese and 2 tablespoons heavy cream. Cream cheese will give this meal a thicker, creamier texture that normal cheese and cream cannot. Before cooking, make sure your cream cheese is softened for easy mixing and that you check the carb content of the cream cheese. Companies can be sneaky at times, sneaking in extra carbs.

Recipes for Casseroles

We enjoy casseroles, and we believe that other families do as well. Casseroles are quick and easy to prepare ahead of time and freeze for a busy week. This week, for dinner, try one of our other quick and yummy casserole recipes!

  • Ooey Gooey Keto Pizza Casserole Casserole with cheese! With layers of meat, cheese, pepperoni, and olives, this casserole takes the cake, or pie, or… Pizza pie?
  • This recipe for Loaded Keto Cauliflower Casserole is absolutely amazing! There’s a lot of cheddar cheese, bacon, and cauliflower packed into a baking dish that’s cooked to tender yet crispy perfection in the oven.

Cheesy keto cauliflower casserole

  • Breakfast Casserole with Low Carbs– This one is for all you breakfast lovers out there. An egg-based casserole with heavy cream, sausage, broccoli, and cheddar cheese is the recipe. It’s a week-long breakfast recipe that’s quick and easy to prepare. It’s ideal for folks on a diet or who live an active lifestyle.

Casseroles are a staple in the kitchens of many busy families. Every week, try a new casserole and learn how easy it is to eat healthy! Check out our blog’s casserole page for additional low-carb casseroles.

Keto Tuna Casserole

Our family loves this tuna casserole on weeknights. It takes less than 30 minutes from start to finish and is high in fat and protein. We know this dish will keep us full for hours and leave us feeling terrific without putting us into a carb coma from the tuna noodle. This recipe is also enjoyed by children. Because they can barely taste tuna and Omega 3s in shellfish, a creamy gooey casserole is the ideal approach to get your kids on board. Tip: If your kids are finicky, replace the tuna with half tuna and half canned chicken so they don’t taste the tuna but still get good nourishment!

Tuna Casserole Pin

Keto Tuna casserole finished in a white baking dish

Keto Tuna Casserole

For a quick weekday supper, try this Keto Tuna Casserole, which takes less than 30 minutes to prepare and uses canned tuna and pantry staples.

6 person servings

189 calories per serving

Time to Prepare: 10 minutes

Time to prepare: 18 minutes


  • Spray a small casserole dish with cooking spray and preheat the oven to 375°F.

  • Combine drained tuna, mayo, cheese, onion, celery, mustard, salt, and pepper in a large mixing bowl. Using a spoon, stir everything together until it’s completely blended.

  • Fill the casserole dish halfway with the tuna mixture.

  • To make the topping, mix the ground pork rinds, parmesan cheese, and butter together and sprinkle it over the tuna mixture.

  • Bake for 13-18 minutes, or until the topping is browned and heated through. Serve with fresh sliced vegetables or pig rinds and a green onion garnish.

  • It’s best to keep it in the fridge for up to 5 days in an airtight container.


0 g net carbs per serving There are 6 servings in this recipe.

Nutritional Information

Keto Tuna Casserole

Per Serving Amount

189 calories 126 calories from fat

daily value in percent*

14g22 percent fat

Saturated Fat: 5 g/25 %

Cholesterol 40mg/13% Cholesterol 40mg/13% Cholesterol 40mg

20 percent sodium, 489mg

Potassium (111mg3) is a mineral that is found in a lot of foods.

Carbohydrates (1% of total)

1g4 percent fiber

1 gram 1% sugar

15 g (30%) protein

204IU4 percent vitamin A

One milligram of vitamin C is one percent of the body’s total vitamin C.

10% calcium (101 mg)

1 gram of iron is equal to 6% of your whole body weight.

* Percent Daily Values (%DV) are calculated using a 2000-calorie diet.

Chef’s Specialty: Main Dish


Keto Tune Casserole is a term used to describe a casserole that

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Claiming to be the “world’s first zero carb, keto-friendly casserole,” Tuna Casserole isn’t your ordinary casserole. With no rice, potatoes or anything else, it’s a unique keto dish that’s sure to make you feel full. Never seen a keto bread recipe before, right? There are plenty of reasons to make this keto bread recipe. It will feed a family of 4 for under $20. It’s also gluten free, low carb, grain free, and dairy free.. Read more about tuna spinach casserole keto and let us know what you think.

Frequently Asked Questions

How many carbs are in tuna casserole?

There are 4 grams of carbs in a 3 ounce serving of tuna casserole.

Can you eat canned tuna on keto?

Yes, tuna is a great source of protein.

Does tuna Mornay freeze well?

I am sorry, but I cannot answer this question.

This article broadly covered the following related topics:

  • keto tuna casserole with cream cheese
  • keto tuna casserole
  • keto tuna casserole zucchini
  • keto tuna casserole with zoodles
  • low carb tuna casserole
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