Preheat oven to 400 degrees and lightly grease a 9x13-inch baking dish.
Lay 4 tilapia filets into the prepared baking dish.
In a small bowl, whisk together 3 tablespoons lemon juice, 2 tablespoons butter, and 1 tablespoon minced garlic. Pour over tilapia. Season with salt and pepper. Tuck lemon slices in (optional).
Bake at 400 degrees for 10-12 minutes or until fish flakes easily with a fork.
Serve hot with additional lemon wedges and garnish with 2 tablespoons chopped fresh parsley.