Brush the tilapia fillets with oil on both sides, season with Creole seasoning to taste, then place into a 9x13-inch baking dish.
Bake in the preheated oven until the flesh is no longer translucent, and the fish flakes easily with a fork, about 10 minutes.
Meanwhile, melt the butter in a small saucepan over medium heat. Stir in the garlic, and cook until the garlic has softened and the aroma has mellowed, about 2 minutes. Stir in the Alfredo sauce and bring to a simmer. Reduce the heat to low, and keep warm until the fish is ready. Pour the sauce over the fish to serve. Sprinkle with additional Creole seasoning if desired.