Preheat your oven to 350°F.
In a 9×13-inch baking dish, pour in the undrained can of sliced peaches, spreading them out evenly to cover the bottom.
Sprinkle the yellow cake mix uniformly over the layer of peaches, ensuring the entire surface is coated.
Arrange the butter slices evenly over the cake mix, spacing them out so they melt uniformly as the cake bakes.
Bake for 40 to 45 minutes, or until the top is a golden brown and the mixture is bubbling around the edges. Allow to cool slightly before serving warm, or enjoy at room temperature for a comforting treat.