Heat the coconut oil in a large skillet over medium heat until fully melted and shimmering.
While the oil heats, combine the flour and lemon pepper seasoning in a shallow dish. Dredge each piece of haddock in the mixture, coating both sides evenly and gently shaking off any excess.
Working in batches, carefully place the fish into the hot oil without overcrowding the pan. Cook for 3–4 minutes, until the underside is golden and the fish releases easily from the skillet.
Flip the fish carefully and cook for another 3–4 minutes, until golden and cooked through. The fish should flake easily with a fork and reach an internal temperature of 145°F.
Transfer the cooked fish to a serving plate and repeat with the remaining pieces. Garnish with lemon wedges and serve hot.