The being known as Q is an extremely powerful and ancient god-entity with control over time, space and reality itself. Q took an interest in humanity, believing the species to be "The Ones" who could save all existence, including that of the Continuum itself, from obliteration at the hands of Them.
Q and other members of the Q Continuum claim to be omniscient and omnipotent, and by human standards, this would appear to be true. However, it has become apparent that there are beings as high above the Q as the Q are above humanity. He is employed by the Old Gray