Celia S. Friedman, known by her pen name C. S. Friedman, is an acclaimed American speculative fiction author. Born on January 12, 1957, she originally embarked on a career as a costume designer before transitioning to a full-time writing career in 1996. Since 1986, Friedman has published fourteen novels and numerous short stories, including her 2021 collection, The Dreaming Kind. She has also contributed to the White Wolf's Vampire: The Masquerade role-playing game with a sourcebook.

Her literary prowess was recognized in 1988 when she was nominated for the John W. Campbell award for Best New Writer, now called the Astounding Award. Her novel This Alien Shore gained further acclaim as a New York Times Notable Book of the Year in 1998. In 2011, The Coldfire Trilogy was a finalist for NPR's Science Fiction and Fantasy Vote.

In 2022, Bohemia Group expressed interest in developing a television series based on The Coldfire Trilogy.