Preheat your grill to 400°F (medium-high heat) or preheat your oven to 400°F.
Tear four large sheets of heavy-duty aluminum foil, about 12 to 14 inches long.
Place one salmon fillet in the center of each foil sheet.
Drizzle each fillet with olive oil.
Season generously with salt and black pepper.
Sprinkle minced garlic evenly over each salmon fillet.
Top with fresh dill and two or three lemon slices.
Place one tablespoon of butter on top of each fillet.
Fold the foil tightly around the salmon, sealing the edges to create individual packets.
Grill the Lemon-Dill Salmon Foil Packets for 12–15 minutes, or bake for 15–18 minutes, depending on thickness.
Carefully open the packets to avoid escaping steam.
Garnish with additional fresh dill and fresh lemon wedges before serving