Heat the oven to 425ºF. Stir 4 tablespoons melted unsalted butter, 1 tablespoon lemon juice, 4 finely chopped garlic cloves, ½ teaspoon dried thyme, ½ teaspoon paprika, and ¼ teaspoon black pepper together in a small bowl.
Pat 1 ½ pounds tilapia fillets dry with paper towels, then season all over with 1 ½ teaspoons kosher salt. Place in an even layer in a 9x13-inch baking dish, they can overlap slightly if needed. Spoon the butter mixture evenly over the tilapia.
Bake until the tilapia is just cooked through, opaque, and flakes easily, 18 to 20 minutes. Garnish with 1 tablespoon coarsely chopped fresh parsley leaves. Serve the tilapia with the sauce in the baking dish and lemon wedges.
