This blackened mahi mahi is a 15-minute fish dish that’s packed with Southern flavor thanks to an easy homemade Cajun spice rub. It’s great for busy weeknight dinners!
Serve mahi mahi over jasmine rice and borrow the mango salsa from my mango chicken recipe. If you love the spicy flavors in this recipe, you might also like my Jamaican jerk chicken!

Mahi mahi: fun to say and delicious to eat. This flaky fish only sounds fancy, but it’s truly one of the easiest I’ve ever cooked. Juicy mahi mahi filets soak up the flavor in today’s homemade blackened seasoning rub like sponges! Just add a side of fluffy rice or roasted veggies. It’s a ticket to the south on a plate.
This Blackened Mahi Mahi Is a Real Catch!
- Quick and easy. Blackened mahi mahi is proof that you can cook a five-star meal in 15 minutes with one pan and the easiest ingredients ever.
- Authentic Southern flavors. The spice rub in this recipe is smoky and a little spicy, reminiscent of the flavors you’ll find in Creole dishes like jambalaya and gumbo.
- Cook once, eat twice (or three times). This blackened mahi mahi is wonderful served hot from the pan as-is. It’s also good for meal prep. Leftovers taste great in tacos, salads, and more!

What You’ll Need to Make This Recipe
Here are quick notes on the ingredients in this mahi mahi recipe. Be sure to scroll to the printable recipe card for the full list with amounts, followed by a step-by-step overview with photos.
- Mahi Mahi – You can find mahi mahi in filets, or buy a whole side and cut it into filets at home. When buying mahi mahi, try to look for fish without signs of darkness or discoloration.
- Olive Oil – Helps the spices adhere to the fish. You can use another cooking oil or butter if you’d like.
- Lemon Wedges – For garnish.
What Is Mahi Mahi?
Mahi mahi is a firm fish with a meaty, crab-like texture and mild flavor. I like cooking with it since it’s not overly fishy. If you can’t find mahi mahi where you are, substitute another mild white fish with firm meat, like halibut or tilapia. You may need to adjust the searing time in this case.

Homemade Blackened Seasoning
Blackening is a Cajun cooking technique where meat, like fish or chicken, is seasoned and then seared quickly in a hot skillet. The combination of the spices and high heat gives the meat a charred or “blackened” appearance.
You can use a store-bought spice mix, or you can make my easy homemade blackened seasoning from the following:
- Aromatics – I use a combination of onion powder and garlic powder. Substitute all of one for the other if needed.
- Sugar – While coconut sugar or brown sugar isn’t mandatory in this recipe, it does add a nice “blackened” appearance.
- Heat – Chili powder and paprika (sweet or smoked). For a spicier blend, add a little cayenne pepper.
- Herbs – Dried basil and thyme.

Frequently Asked Questions
The exact cooking times in this mahi mahi recipe may vary, depending on the size and thickness of the filets. Whenever possible, purchase filets that are equal in size for even cooking.
Sure! If you don’t have blackened seasoning, Cajun spice makes a good substitute (I use Cajun seasoning in my grilled tilapia recipe). You could even try jerk seasoning.

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Prepare the spices. In a shallow bowl, combine the onion powder, coconut sugar, smoked paprika, chili powder, garlic powder, dried basil, and dried thyme.
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Season the mahi mahi fillets. Pat dry the mahi mahi fillets. Season the fish with salt and pepper to taste. Then, coat the fish with the prepared spice mixture on all sides.
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Cook the fish. Heat the olive oil in a large skillet over medium-high heat. Cook the fish for 2-3 minutes per side, or until the inner temperature reaches 130°F to 137˚F. If you do not have a thermometer, the cooked fish should flake easily and appear opaque in color.
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Enjoy! Remove the mahi mahi from the skillet and let it rest for a few minutes. Serve the fish fillets warm, drizzled with lemon juice.
- Coconut or brown sugar is not mandatory in this recipe, but it will add that nice “blackened” appearance.
- When buying mahi mahi fillets, look for fish that has no darkness or discoloration.
- Cooking time of mahi mahi may vary, depending on the size and thickness. If possible, purchase fillets that are equal in size.
- I like to serve my mahi mahi with mango salsa.
Calories: 219kcal | Carbohydrates: 3g | Protein: 32g | Fat: 8g | Saturated Fat: 1g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 5g | Cholesterol: 124mg | Sodium: 162mg | Potassium: 754mg | Fiber: 1g | Sugar: 1g | Vitamin A: 712IU | Vitamin C: 0.3mg | Calcium: 42mg | Iron: 3mg
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.
How to Make Blackened Mahi Mahi
Traditional blackening recipes call for pan-searing with butter (the milk solids in the butter actually contributed to the “black” crust). I prefer to cook with olive oil, but you can absolutely swap it for butter to go the more authentic route.


- Season the fish. Start by whisking together the blackened spices in a bowl. Pat the mahi mahi filets dry, season with salt and pepper, and then rub the fish with the blackened seasoning on all sides.


- Pan-sear the fish. Next, add the seasoned fish to a skillet (or use cast-iron) with olive oil. Cook over medium-high heat for 2-3 minutes per side. When the internal temperature reads 130ºF on an instant-read thermometer, your mahi mahi is cooked. Otherwise, mahi mahi is similar to salmon in that it flakes easily with a fork when it’s done.
- Serve! Enjoy your spicy blackened mahi mahi warm with rice, topped with a squeeze of lemon juice.
Can I Grill Mahi Mahi?
Absolutely! I have a recipe for grilled mahi mahi with in-depth instructions. It’s as easy as grilling the fish over 425-450ºF for about 4 minutes per side (or less, check the fish early to be safe!). The fresh balsamic tomato salad in that recipe also goes great with blackened mahi mahi.
There’s also the option to make baked mahi mahi on a sheet pan. Add your favorite quick-cooking veggies, like zucchini, bell peppers, and red onion, and garbanzo beans (chickpeas) for an all-in-one dinner.

Storing and Reheating Leftover Fish
- Refrigerate. Baked mahi mahi can be stored in an airtight container in the fridge for 2-3 days.
- Reheat. Warm the fish, covered in foil, in a 275ºF oven until it’s heated through. Be careful not to overcook it.