Abstract: An illuminator (20) and a liquid container assembly including the illuminator are disclosed. The illuminator (20) includes a light source (24), a power source and a coupling portion (22). The coupling portion (22) is flexibly compressible such that the illuminator (20) is easily inserted and secured within a space of a suitable size provided on the surface of the liquid container. The illuminator (20) can be used in combination with various liquid container such as drinking glass or liquid bottle to provide illumination to the liquid in the container.