This Blackened Mahi Mahi is incredibly juicy, flaky and flavorful! An easy homemade Cajun seasoning takes this fish from good to exceptional. This Mahi Mahi recipe is super quick and easy but feels fancy and sophisticated!

Blackened mahi mahi on plate

Why You’ll Love This Recipe

  • This blackened mahi mahi is incredibly delicious!
  • This recipe takes only 20 minutes from start to finish.
  • The Cajun seasoning adds so much flavor.
  • This fish can be as spicy or mild as you prefer.
  • This recipe is Whole30 compliant, Paleo, gluten free, dairy free, Keto, low carb, and sugar free.
  • Check out this Pan Seared Chilean Sea Bass and this Candied Salmon for more delicious seafood recipes!

Ingredients & Substitutions

The homemade Cajun seasoning is a little spicy and so flavorful! Each specific spice and seasoning adds a unique and delicious flavor. For a less spicy seasoning, cut down on paprika and cayenne.

Fresh mahi mahi is incredibly flavorful. I highly recommend fresh not frozen fish if possible. If not, thaw frozen mahi mahi before making recipe. Costco sells Kirkland brand frozen mahi mahi.

The olive oil is a heart healthy cooking fat. It helps sear the fish and create a crispy exterior. If desired, avocado oil, ghee or butter can be used as well.

A squeeze of lemon juice adds the perfect amount of tartness on top!

What is Mahi Mahi?

Mahi mahi is a beautiful brightly colored fish. Its name is Hawaiian and translates to “strong strong”. This fish swims next to boats like dolphins do.

Mahi mahi are usually 4 to 6 pounds in weight. They are well known for their bright blue and gold coloring.

This healthy fish is lean and has a slightly sweet flavor. It can be grilled, broiled and pan seared. It is commonly served as mahi mahi tacos or in sandwiches.

Cajun Seasoning

This homemade Cajun seasoning is easy, healthy and delicious. While Cajun seasoning can be bought, this homemade version is so flavorful. Unlike store bought varieties, making homemade seasoning can be customized. No added sugars or preservatives needed!

Check out this Gluten Free Cajun Seasoning for more information.

Gluten free Cajun seasoning on a white plate

Taste & Texture

This blackened mahi mahi has a delicious Cajun flavor. While it is not overpowering, it is relatively strong. Feel free to alter Cajun seasoning to suit your taste.

This fish is juicy and easily flakes. It is not dry and not dense.

How to Make

Step 1

First, combine all Cajun seasoning ingredients in a small bowl.

Spices for Paleo Cajun seasoning

Step 2

Remove skins from mahi mahi. Pat fish dry with paper towels.

Raw mahi mahi

Step 3

Rub both sides of fish with seasoning.

Cajun fish seasoning

Step 4

Add olive oil to a large skillet over medium heat. Once oil is hot, place fish in skillet.

Step 5

Cook for 5 minutes. Then flip and cook another 4 to 5 minutes or until fish is flaky and has reached an internal temperature of 137 degrees Fahrenheit.

Flaky mahi mahi on plate

Step 6

Lastly, remove fish from pan. Squeeze lemon juice on top if desired.

Oven Method

To make this in an oven, follow these steps:

  • Preheat oven to 400 degrees Fahrenheit. Spread 1 tablespoon of olive oil on pan.
  • Combine Cajun seasoning.
  • Remove skins from fish. Pat dry with paper towels.
  • Rub seasoning on both sides of fish.
  • Place fish on oiled pan.
  • Bake for 11 to 14 minutes or until internal temperature has reached 137 degrees Fahrenheit and fish is flaky.

Expert Tips & Tricks

Pat fish completely dry with paper towels. This allows the fish to get a nice sear on it.

Thoroughly coat both sides of fish with seasoning.

Use a meat thermometer to measure internal temperature of fish. Cook until internal temperature is 137 degrees Fahrenheit.

Blackened mahi mahi with potatoes and green beans

Buying Mahi Mahi

Here are some things to look for when picking out this fish.

Brightly colored skin

Pink hued meat

Meat should be firm

How to Serve & Store

Serve hot from the pan! Since fish is commonly served with chips, these Whole30 French Fries and Whole30 Mashed Potatoes are great side dishes. In addition, this Roasted Cauliflower and Asparagus is a tasty option.

Frequently Asked Questions

What does blackened mahi mahi taste like?

Blackened mahi mahi has a Cajun flavor and a slightly sweet flavor.

What is meant by blackened fish?

Blackened fish refers to a fish with Cajun seasoning.

Is mahi mahi healthy?

Yes, mahi mahi is lean, healthy and contains many vitamins and nutrients.

Should I take off the skin?

Yes, remove skin.

How do I know when it is done cooking?

Use a meat thermometer to determine internal temperature. Cook until a temperature of 137 degrees Fahrenheit is reached.

Blackened fish on plate

You May Also Like

If you make this recipe, I would really appreciate a review! You can find me on InstagramFacebook, and Pinterest. I would love for you to follow along! 

Blackened mahi mahi on plate

Get the Recipe: Blackened Mahi Mahi

This Blackened Mahi Mahi is incredibly flavorful! A homemade Cajun seasoning elevates this fish. It is pan seared for the perfect texture. This fish is quick, easy, healthy and delicious!
5 from 14 votes


Cajun Seasoning

Mahi Mahi

  • 2 fillets mahi mahi, fresh or thawed
  • 2 tbsp olive oil, or butter
  • squeeze lemon juice


  • First, combine all Cajun seasonings in small bowl. Stir to combine.
  • Remove skins of mahi mahi fillets. Pat fillets dry with paper towels. Use hands to coat both sides of fish with Cajun seasoning.
  • In a large skillet over medium heat, add olive oil. Once oil is hot, add mahi mahi to skillet.
  • Cook for 5 minutes. Then, carefully flip and cook another 4 to 5 minutes or until fish is flaky and has reached an internal temperature of 137 degrees Fahrenheit.
  • Finally, remove from pan. Squeeze lemon juice on fish if desired.


  • This Cajun seasoning has a kick to it.  Feel free to adjust to your taste.
  • Thoroughly coat both sides of fish with seasoning.
  • If using frozen mahi mahi, allow it to thaw before use.
  • Remove skins from fish.
  • Fish is done when it has reached an internal temperature of 137 degrees Fahrenheit and easily flakes.
  • Store leftovers in the fridge for up to 3 days.
Calories: 288kcal, Carbohydrates: 4g, Protein: 32g, Fat: 16g, Saturated Fat: 2g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 10g, Cholesterol: 124mg, Sodium: 734mg, Potassium: 805mg, Fiber: 2g, Sugar: 1g, Vitamin A: 1321IU, Vitamin C: 8mg, Calcium: 61mg, Iron: 3mg

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