Preheat your grill to medium-high heat, around 400-450°F (200-230°C). Tear off four large sheets of heavy-duty aluminum foil, each about 12 inches long. Lightly grease the foil with butter or non-stick cooking spray.
In a small bowl, combine the olive oil, lemon juice, garlic, dill, salt, and pepper. Whisk the ingredients together to create a flavorful marinade. Place the salmon fillets onto the prepared foil sheets and brush or spoon the marinade over the top, making sure to evenly coat the fish.
If desired, place a few lemon slices on top of the salmon. Fold the foil over the salmon, crimping the edges to create a tight seal and form a packet.
Place the foil packets directly onto the preheated grill grates. Close the grill lid and cook for 15-20 minutes, or until the salmon is cooked through and flakes easily with a fork. The internal temperature should reach 145°F (63°C).
Carefully remove the foil packets from the grill, being cautious of the hot steam. Open the packets and transfer the salmon to plates. Serve the Grilled Salmon in Foil immediately, garnished with any remaining lemon slices, fresh herbs, or your favorite sides.
