Grilled Blackened Mahi Mahi
by Sommer Collier — last updated on Jan 27, 2025 
Best Blackened Mahi Mahi—This quick and easy grilled mahi recipe features our homemade blackening seasoning blend, which is made with brown sugar, dried herbs, smoky paprika, and spicy cayenne pepper. From start to finish, dinner is ready to serve in under 20 minutes with your favorite Southern side dishes!
Why We Love this Blackened Mahi Mahi Recipe
We have a classic blackened seasoning recipe here on the site, as well as a tweaked version specific to grilled chicken. But blackening seasoning can go on anything from grilled vegetables, garlic bread, and of course, everyone’s favorite seafood! We especially like blackened seasoning on heartier fish with a more firm texture. This Blackened Mahi-Mahi recipe is a great example!
Mahi is a firm white fish with a distinct, mildly sweet flavor. It is a beautiful fish for grilling, especially when rubbed down in our homemade blackening seasoning! Prep takes barely any effort, and the fillets are grilled to moist, fork-flaky, and super-flavorful perfection in under 10 minutes.
Ingredients You Need
- Mahi Mahi Filets – fish fillets or steaks, about 1/2-inch thick, thawed and patted dry
- Olive oil – or other high-heat oil like avocado oil or canola oil
- Spices – smoked paprika, onion powder, salt, black pepper, garlic powder, dried thyme, dried oregano, cayenne pepper
- Light brown sugar – to caramelize the fish and balance the spicy and smoky flavors
How to Grill Blackened Mahi-Mahi
Preheat the grill. Pat the Mahi Mahi fillets with a paper towel to remove excess moisture. Then, brush them with olive oil on all sides.
Combine the blackened seasoning spices in a small bowl.
Then, sprinkle the blackened seasoning over the Mahi fillets on all sides. Gently rub to ensure the seasoning sticks to the oil.
Place the Mahi steaks on the hot grates and grill for a few minutes on each side, until the fish releases easily from the grates.
Get the Complete (Printable) Grilled Blackened Mahi Mahi Recipe Below. Enjoy!
Pro Tip: If it’s sticking to the grill, it’s probably not quite ready to flip.
Flip the fish and continue to grill for another 3-4 minutes, for a total of 7-9 minutes cook time. Allow the fillets to rest for 2-3 minutes before serving.
Recipe Variations
- Other fish – Our wonderful blackening spice blend can be used on other firm fish like red snapper or cod. Season and grill the fish as you would Mahi Mahi.
- More or less spicy – This recipe uses only 1/4 teaspoon of cayenne pepper. It adds heat but without melting your mouth. You can increase or decrease the amount used, or omit it entirely.
- Without grilling – No grill? No problem! Sear the seasoned filletsin a cast iron skillet on the stovetop or bake them in the oven.
Serving Suggestions
Fabulously flavorful blackened Mahi Mahi pairs well with light but satisfying starches like white rice or creamy polenta. Or make it a low-carb meal with roasted cauliflower rice! For something more filling, consider serving with mashed sweet potatoes or creamy pasta dishes like fettuccine Alfredo.
The great Southernness of the dish also makes it delightful with almost any down-home side dishes. Pair the fillets with collard greens, fried okra, corn spoon bread, or refreshing coleslaw. Or even a plate of fresh steamed or roasted veggies like broccoli, cauliflower, carrots, or other vegetables are a great option!
Meaty Mahi Mahi fillets are also tasty in fish tacos or loaded onto hamburger buns or hoagie rolls for hearty fish sandwiches. Don’t skip the homemade peach mango salsa or remoulade sauce!
Frequently Asked Questions
There is definitely some nice heat here from the cayenne pepper. But it is not overwhelming, and is more of a mellow, smoky-spicy flavor rather than just straight-up fire. Feel free to adjust the amount of cayenne to fit your tastes!
That being said, folks that are sensitive to spicy foods might think this seasoning blend is a bit too hot for their liking. You can adjust the heat to your taste.
Mahi Mahi meat is firm with large, hearty flakes. Grilling it brings out its sweet flavor, which is delicious with the bold blackening spices.
I prefer to thaw my fillets before cooking. This is best done overnight in the fridge in a sealed container. But yes, you can technically grill the Mahi Mahi from frozen. Note that it will take a few minutes longer on each side. Also, keep a close eye on them to be sure the fillets don’t stick to the grill grates.
Leftover grilled fish will keep well in an airtight container in the fridge for up to 2-3 days. Enjoy leftovers cold on salads or sandwiches. Or briefly reheat the fillets on the grill or in the microwave in short 20-second bursts at 50% power.
Looking for More Easy Seafood Recipes? Be Sure to Try:
- Grilled Grouper with Orange and Olives
- Crab Stuffed Mushrooms (with Ritz Crackers)
- Mussels Recipe with Blue Cheese
- Garlic Lime Roasted Shrimp Salad
- Hawaiian Ahi Poke
- Shrimp Mac and Cheese
- Lemon Pepper Grilled Cod
- Sweet and Sour Salmon With Pineapple
- Pescado Zarandeado (Mexican Grilled Red Snapper)
- How to Grill Salmon (with Marinade)
- Sweet and Sour Grilled Salmon with Pineapple Salsa
Grilled Blackened Mahi Mahi
Ingredients
- 4 Mahi Mahi fillets or steaks
- 1 tablespoon olive oil
- 2 tablespoons smoked paprika
- 1 ½ teaspoons onion powder
- 1 teaspoon salt
- 1 teaspoon cracked black pepper
- 1 teaspoon light brown sugar
- ½ teaspoon garlic powder
- ½ teaspoon dried thyme
- ½ teaspoon dried oregano
- ¼ teaspoon cayenne pepper
Instructions
- Preheat the grill to 400-450°F. Use a paper towel to pat the Mahi Mahi fillets to remove any excess moisture. Then brush them with olive oil on all sides.
- In a small bowl, combine the smoked paprika, onion powder, salt, pepper, sugar, garlic powder, dried thyme, dried or oregano, and cayenne pepper. Mix well. Sprinkle the blackened seasoning over the Mahi fillets on all sides. Gently rub to make sure the blackened seasoning sticks to the oil.
- Once the grill is hot, place the Mahi steaks on the hot grates and grill for 4-5 minutes, until the fish releases easily from the grates. If it's sticking, it's most likely not quite ready to flip.
- Flip the fish and continue to grill for another 3-4 minutes, for a total of 7-9 minutes cook time. Allow the fillets to rest for 2-3 minutes before serving.
This recipe was a hit at our house! And was so easy to make. Can’t wait to make this again!
This tasted better than expected, we absolutely cleaned our plates!! Best fish ever!
This is so good!! Love blackened chicken & fish! It’s so flavorful, especially from being on the grill!