IAO may mean several things:* The Information Awareness Office, a branch of the U.S. Defense Advanced Research Projects Agency. The International Astronomy Olympiad, an internationally recongnized annual astronomy competition for high-school students. The Indian Astronomical Observatory, home of the highest telescope in the world. The initials of Isis, Apophis and Osiris, used as a magical formula in the Hermetic Order of the Golden Dawn. A god-name found in the Greek Magical Papyri, where i… (More on Iao)