Prep the fish. Pat the catfish fillets dry with paper towels. Brush or rub the melted butter evenly over both sides.
Make the coating. In a shallow dish, combine the cornmeal, Cajun seasoning, salt, and black pepper.
Coat the catfish. Dredge each fillet in the cornmeal mixture and press gently so the coating sticks to both sides.
Air fry. Lightly spray the air fryer basket or tray with oil. Arrange the fillets in a single layer with space between them, then lightly spray the tops with oil.
Cook and flip. Air fry for 14 minutes, carefully flipping halfway through.
Check for doneness. If needed, cook for another 3–4 minutes, until the crust is golden and the thickest part of the fish reaches 145°F.
Serve. Serve immediately with lemon wedges.
Notes
Pat the fish dry so the coating sticks better.
Don’t overcrowd the air fryer basket.
Flip carefully so the cornmeal crust stays intact.
If the catfish has a stronger flavor, soak it in milk or buttermilk for about 30 minutes, then dry thoroughly before coating.
Thaw frozen catfish completely before cooking.
Store leftovers in the refrigerator for up to 3 days and reheat in the air fryer at 350°F.