- MEMORY, SORROW AND THORN
- Book 1: The Dragonbone Chair (Hardcover 1988, Paperback 1989)
- Book 2: Stone of Farewell (Hardcover 1990, Paperback 1991)
- Book 3: To Green Angel Tower (Hardcover 1993)
Book 3 was split into 2 parts for paperback publication (1994):
- To Green Angel Tower, Part 1 and To Green Angel Tower, Part 2 (US Edition)
- To Green Angel Tower: Siege and To Green Angel Tower: Storm (UK edition)
- Novelette: The Burning Man (Legends (book)) 1998
- Graphic Novel: The Burning Man
- Book 1: City of Golden Shadow (Hardcover 1996, Paperback 1998)
- Book 2: River of Blue Fire (Hardcover 1998, Paperback 1999)
- Book 3: Mountain of Black Glass (Hardcover 1999, Paperback 2000)
- Book 4: Sea of Silver Light (Hardcover 2001, Paperback 2002)
- Novelette: The Happiest Dead Boy in the World (Legends II 2004)
- Book 1: Shadowmarch (Hardcover 2004, Trade Paperback 2005, Mass-Market Paperback 2006)
- Book 2: Shadowplay (Hardcover, 2007, Trade Paperback 2008, Mass-Market Paperback 2009)
- Book 3: Shadowrise (Hardcover, 2010, Trade Paperback 2010)
- Book 4: Shadowheart (Hardcover, 2010)
- THE ORDINARY FARM ADVENTURES
Young-adult, written with Deborah Beale (his wife)
- Book 1: The Dragons of Ordinary Farm (Hardcover, June 2009)
- Book 2: The Secrets of Ordinary Farm (eBook, August 2011)
- Book 3: (forthcoming)
- Book 4: (forthcoming)
- Book 5: (forthcoming)
- THE BOBBY DOLLAR BOOKS
Noir fantasy thrillers
- Book 1: The Dirty Streets of Heaven
- Book 2: Happy Hour in Hell
- Book 3: Sleeping Late on Judgement Day (forthcoming)
- Tailchaser’s Song (Hardcover 1985, Paperback 1986)
- Child of an Ancient City (Paperback 1992, written with Nina Kiriki Hoffman)
- Caliban’s Hour (Hardcover 1994)
- The War of the Flowers (Hardcover 2003, Paperback 2004)
- Rite: Short Work (Hardcover, 2006) Subterranean Press. Published in January 2007.
- Rite: Short Work (Trade Paperback, May 2008) Subterranean Press/Far Territories. Reprint of the limited hc edition without the non-fiction pieces. The reprint only contains the short stories.
- Mirrorworld 2 issues. Series was cancelled after two issues when the publisher went out of business.
- The Next 6 issue mini-series published by DC Comics. Published between July and December 2006.
- Aquaman: Sword of Atlantis published by DC Comics. Williams replaced writer Kurt Busiek with issue #50 in March 2007. His run lasted till issue #57 when the comic was cancelled.
- Ibis the Invincible: The Helmet of Fate one-shot published by DC Comics in 2007.