Gregory Keyes is a writer of science fiction and fantasy who has written both original and media-related novels under both the names "J. Gregory Keyes" and "Greg Keyes". He is famous for his quartet "The Age of Unreason", a steampunk/alchemical story starring Benjamin Franklin and Sir Isaac Newton. He wrote the Babylon 5 Psi Corps trilogy, a history of the Psi Corps and a biography of Psi Corps member Alfred Bester.
In 2009 it was announced that Keyes would be writing two novels based on the successful computer game The Elder Scrolls IV: Oblivion. The first of these, "The Infernal City", was published by Random House in November of 2009. "Lord of Souls", the second Elder Scrolls novel, was published by Del Rey on September 27, 2011.