Flewelling grew up in northern Maine, United States, and has since lived on both coasts and traveled around the world, all experiences that are reflected in her writing. She has worked as a teacher, a house painter, a necropsy technician, and a free-lance editor and journalist. She has been married to Douglas Flewelling since 1981, and has two sons. She currently lives in Redlands, California, where she continues to write, and offers lectures and creative writing workshops at the University of Redlands .

Her first Nightrunner novel, Luck in the Shadows, was a Locus Magazine Editor's Pick for Best First Novel and a finalist for the Compton Crook Award. Her novels Traitor's Moon (2000) and Hidden Warrior (2004) were both finalists for the Spectrum Award. Her novels are currently published in 13 countries, and in 2005, the first volume of the Japanese language version of Luck in the Shadows was published. Ms. Flewelling is accessible to readers through her web site, her Live Journal blog, her Yahoo! group, and numerous guest appearances at conventions including Comic-Con and Smith College's ConBust . Her work has been praised by other notable fantasy authors, including George R. R. Martin, Orson Scott Card, Elizabeth Hand, Robin Hobb, and Katherine Kurtz . Independent film company Csquared Pictures has acquired film rights to the first three books in the Nightrunner series, but they have not yet started production.

Many readers find particular interest in Ms. Flewelling's exploration of LGBT and transgender themes. The protagonists of the Nightrunner books are both bisexual: Ms. Flewelling has stated their creation was in response to the near-absence of queer characters in the genre and marginalization of existing ones. Her novels have also drawn academic attention: in an upcoming book, Dr. Jes Battis at the University of Regina uses the master thief-protege relationship in the Nightrunner books and the knight-squire relationship in another fantasy work to explore how queerness manifests in both the historical source material and the contemporary re-imagining in fantasy fiction. By contrast, the Tamir Triad features a protagonist who transforms from one sex and gender to the other, combining elements of psychological drama with ghost story horror.

Novels

Nightrunner Series

• Luck in the Shadows (Bantam Spectra, 1996)
• Stalking Darkness (Bantam Spectra, 1997)
• Traitor's Moon (Bantam Spectra, 1999)
• Shadows Return (Bantam Spectra; June 24, 2008)
• The White Road (Bantam Spectra, May, 2010)
• Casket of Souls (Bantam Spectra, October, 2011)

Tamír Triad

• The Bone Doll's Twin (Bantam Spectra, 2001)
• Hidden Warrior (Bantam Spectra, 2003)
• Oracle's Queen (Bantam Spectra; June, 2006)

Shorts

• "Letter To Alexi" Prisoners of the Night, 1995
• "Raven's Cut" Assassin Fantastic anthology, Martin Greenberg and Alex Potter, ed. DAW books.
• "The Complete Nobody's Guide to Query Letters" Speculations, 1999, reprinted on SFWA website and in The Writer's Guide to Queries, Pitches and Proposals by Moira Allen, Allsworth Press (2001)
• "Perfection" Elemental: The Tsunami Relief Anthology: Stories of Science Fiction and Fantasy, Steven Savile and Alethea Kontis, ed, TOR Books, 2006.