An illuminating bottle closure is removably couplable to a mouth or opening of a bottle. The illuminating bottle closure has a stopper portion that is insertable into the opening of the bottle and a flange portion radiating outwardly from the stopper portion for resting upon a lip of the bottle. A light emitting source and a power source are disposed in the illuminating bottle closure for emitting light into an interior of the bottle. An actuating assembly is also disposed to the illuminating bottle closure for selectively controlling power to the light emitting source. By illuminating a bottle from its interior, the illuminating bottle closure creates an enjoyable visual experience by creating the appearance that the bottle is glowing.