Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.
In a small bowl, whisk together the melted butter, lemon juice, minced garlic, oregano, salt, and black pepper.
Place the salmon fillets on one side of the prepared baking sheet and the asparagus on the other side.
Drizzle half of the lemon garlic butter mixture over the salmon and the other half over the asparagus. Toss the asparagus to coat evenly.
Bake in the preheated oven for 12-15 minutes, or until the salmon flakes easily with a fork and the asparagus is tender.
Serve immediately with lemon wedges on the side for extra flavor.