Katharine Kerr was born in Cleveland, Ohio and given the name Nancy Brahtin. She describes her family feeling more like "British-in-exile" than American. She describes her inability to spell properly using either the British or American systems as a result of having been taught to read solely with British books. While still a schoolgirl, her family moved to Santa Barbara, California. Katharine was horrified to discover first that no major league baseball teams existed there yet (baseball being a great passion of hers along with reading and cats), and then that beaches were considered more important in Southern California than books.
In 1962, she moved to the San Francisco Bay Area, eventually moving to San Francisco itself. She spent time studying at Stanford University but dropped out in the mid-sixties to join in several revolutions. She then worked in several low-paying jobs, including work at a Post Office.
In 1973, she met up with Howard Kerr, an old friend of hers from secondary school. Both shared a love for cats, books and baseball. They were married that same year.
In 1979, a friend gave Katharine her first fantasy-role playing game, which she refers to as "the fatal gift". This gift led her to a fascination with the gaming and fantasy field, which in turn led her to write articles for gaming magazines. She spent time as a contributing editor to Dragon magazine and contributed to gaming modules for both TSR, Inc.; and Chaosium, Inc.
Katharine now dedicates herself exclusively to fiction and is known for her fiction novels, especially her novels of Deverry.
- Daggerspell (1986)
- Darkspell (1987) — later reissued in an "author's definitive edition"
- The Bristling Wood (1989) — US title; issued in the UK as Dawnspell: The Bristling Wood
- The Dragon Revenant (1990) — US title; issued in the UK as Dragonspell: The Southern Sea
- A Time of Exile (1991)
- A Time of Omens (1992)
- Days of Blood and Fire (1993) — US title; issued in the UK as A Time of War
- Days of Air and Darkness (1994) — US title; issued in the UK as A Time of Justice
- The Gold Falcon (2006) - US title; issued in the UK as the fourth book of The Dragon Mage
- The Spirit Stone (2007) - US title; issued in the UK as the fifth book of The Dragon Mage
- The Shadow Isle (2008) - US title; issued in the UK as the sixth book of The Dragon Mage
- The Silver Mage (2009) - US title; issued in the UK as the seventh book of The Dragon Mage
- Palace (1996) — with Mark Kreighbaum (The second book in the series, The Eyes of God, is written only by Mark Kreighbaum)
- Resurrection (1992)
- Freeze Frames (1995)
- Snare (2003)