William G. Gray was born in Harrow, Middlesex, United Kingdom. His mother was an astrologer and psychic consultant. He comes from a long line of churchmen, with his heritage extending back to Archbishop Walter de Gray of York, one of the founders of its famous Minster.

He received much of his early training in the Western Inner Tradition from an associate of Papus. This individual was a Qabbalistic Rosicrucian, and Gray believes that his writings were profoundly influenced by this person's teachings.