Place swordfish in a 9x13-inch baking dish. Place bell pepper slices around the fish. Pour wine over top and sprinkle with shallots. Cover and marinate in the refrigerator for 1 hour.
Preheat the oven to 350 degrees F (175 degrees C). Remove fish from the refrigerator.
Bake in the preheated oven, basting occasionally with the wine marinade, until fish flakes easily with a fork, 20 to 30 minutes.