John Stewart Williamson (April 29, 1908 – November 10, 2006), who wrote as Jack Williamson, was an American science fiction writer, often called the “Dean of Science Fiction” after the death of Robert Heinlein in 1988. Early in his career he sometimes used the pseudonyms Will Stewart and Nils O. Sonderlund. The Science Fiction Writers of America named Williamson its second Grand Master of Science Fiction after Robert Heinlein, presented 1976.

After retiring from teaching full-time in 1977, Williamson spent some time concentrating on his writing, but after being named Professor Emeritus by Eastern New Mexico University (ENMU), he was coaxed back to co-teach two evening classes, “Creative Writing” and “Fantasy and Science Fiction” (he pioneered the latter at ENMU during his full-time professorship days). Williamson continued to co-teach these two classes into the 21st century. After he made a large donation of original manuscripts and rare books from his personal collection to the ENMU library, a special collections area was created to house these and it was named the “Jack Williamson Special Collection.”

In 1994 Williamson received a World Fantasy Award for Lifetime Achievement. The Science Fiction and Fantasy Hall of Fame inducted Williamson in 1996, its inaugural class of two deceased and two living persons. The Horror Writers Association conferred its Bram Stoker Award for Lifetime Achievement in 1998 and the World Horror Convention elected him Grand Master in 2004.

In November 2006, Williamson died at his home in Portales, New Mexico at age 98. Despite his age, he had made an appearance at the Spring 2006 Jack Williamson Lectureship and published a 320-page novel, The Stonehenge Gate, in 2005.