The Illuminating Pouring Spout is a new and improved pouring spout for use and attachment on an open end of a liquid container. The pouring spout bears elastically against the inner wall of the liquid container to hold it in place. The pouring spout contains a power source and a light source in a chamber within the pouring spout. The power source and light source are connected in such a way that when the liquid container is moved, grasped or inverted for pouring the Illuminating Pouring Spout is engaged until it is released or still. The light source may be aimed down into the liquid container and/or aimed outward from the dispensing end of the pouring spout. When engaged, the Illuminating Pouring Spout's visual effects are pleasing to the eyes of nearby observers and are useful for advertising and attracting business.