Preheat the oven to 350 degrees F (175 degrees C). Lay salmon fillet skin-side down on a wide piece of aluminum foil.
Drizzle olive oil and balsamic vinegar over salmon. Sprinkle lemon pepper, lemon juice, and salt on top. Fold foil up and over the fillet, tenting it at the top. Roll top down to seal salmon in foil. Transfer to a baking sheet.
Bake in the preheated oven until salmon flakes easily with a fork, about 1 hour.