Preheat grill to medium-high heat (around 375-450°F) or use a stovetop grill pan.
In a small bowl, mix the olive oil, half of the salt (0.5 tsp), and black pepper to form a marinade.
Rub the marinade onto both sides of the swordfish fillets and let marinate for 20 minutes.
Grill the fillets for 5 minutes per side or until the edges are slightly charred and firm when pressed.
Meanwhile, in another bowl, combine the diced mango, chopped red onion, minced jalapeño, and fresh cilantro.
Add the lime juice and remaining salt to the salsa, adjusting as needed for desired flavor balance.
Serve the grilled swordfish immediately, topped with a generous portion of the mango salsa and a lime wedge for garnish.