John Gregory Betancourt (born October 25, 1963) is an American writer of science fiction, fantasy and mystery novels, as well as short stories. He is also known as the founder and publisher, with his wife Kim Betancourt, of Wildside Press in 1989. Nearly a decade later, they entered the print on demand (PoD) market and greatly expanded their production. In addition to publishing new novels and short stories, they have undertaken projects to publish new editions of collections of stories that appeared in historic magazines.

Prior to establishing the new business, Betancourt worked as an assistant editor at Amazing Stories and editor of Horror: The Newsmagazine of the Horror Field, the revived Weird Tales magazine, the first issue of H. P. Lovecraft's Magazine of Horror (which he subsequently hired Marvin Kaye to edit), Cat Tales magazine (which he subsequently hired George H. Scithers to edit), and Adventure Tales magazine. He worked as a Senior Editor for Byron Preiss Visual Publications (1989–1996) and iBooks.