James D. Macdonald was born in White Plains, New York in 1954, and raised in Bedford, New York, the son of a chemical engineer and an artist. His last significant formal education took place at Archbishop Stepinac High School in White Plains, though he passed through the University of Rochester where he learned that a degree in Medieval Studies wouldn't fit him for anything. He went off to sea "to forget," though he's forgotten exactly what. As an enlisted Boatswain's Mate in the Navy, and later as an officer, he saw the world, and discovered that three quarters of it was water. Some time later, tired of the adventure, he decided to get a job.
As Yog Sysop Macdonald ran the Science Fiction and Fantasy RoundTable on GEnie for two years ('91 to '93). He's since moved on to being Yog Sysop at SFF Net. He lives in New Hampshire, where he learned to drink Moxie and writes science fiction and fantasy for children, teenagers, and adults.