Preheat grill to medium-high heat.
Whisk together olive oil, garlic, salt, and pepper in a small bowl. Brush both sides of swordfish steaks with the mixture.
Place on preheated grill for 3-4 minutes per side or until fish is cooked through (internal temperature should reach at least 145°F).
Remove from heat, let rest briefly before serving. Serve each slice garnished with lemon wedges and fresh parsley if desired.