Combine olive oil, parsley, garlic, salt, black pepper, and red pepper flakes in a bowl. Add shrimp and mix well. Set aside to marinade for 10 minutes.
Preheat an outdoor grill for high heat.
Lay out a large piece of aluminum foil and fold in half. Fold up edges to create a pouch in the middle. Place marinated shrimp in the middle and drizzle with lemon juice. Lightly close pouch.
Cook on the hot grill until shrimp are pink and cooked through, 8 to 10 minutes. Serve with lemon wedges.
