Diane Duane is an American science fiction and fantasy author, long based in Ireland. Her works include the Young Wizards young adult fantasy series and the Rihannsu Star Trek novels. She has been a writer of science fiction, fantasy, TV, and film for more than forty years. Besides the creation of the Young Wizards fantasy series, she is known for the "Middle Kingdoms" epic fantasy series, and numerous stand-alone fantasy or science fiction novels.

Her career has included extensive work in the Star Trek universe, and many scripts for live-action and animated TV series on both sides of the Atlantic, as well as work in comics and computer games. She has spent a fair amount of time on the New York Times Bestseller List and has picked up various awards and award nominations here and there.

She lives in County Wicklow, in Ireland, with her husband of more than thirty years.