Poetry

• Immrama (1988)
• The Unexplored Ocean (1994)
• Altered States (1999)

Prose

• The Conjuror's Game (1990)
• Fintan's Tower (1991)
• Saint Tarvel's Bell (1992)
• The Snow-Walker trilogy:
• The Snow-Walker's Son (1993)
• The Empty Hand (1995)
• The Soul Thieves (1996)
• The Candle Man (1994)
• The Hare And Other Stories (1994)
• Belin's Hill (1997)
• The Book of the Crow series:
• The Relic Master (1998)
• The Interrex (1999)
• Flain's Coronet (2000)
• The Margrave (2001)
• The Lammas Field (1999)
• Darkwater Hall (2000)
• Corbenic (2002)
• The Oracle trilogy:
• The Oracle (US title: The Oracle Betrayed) (2003)
• The Archon (US title: The Sphere of Secrets) (2004)
• The Scarab (US title: Day of the Scarab) (2005)
• Darkhenge (2005)
• The Weather Dress (2005)
• Incarceron series
• Incarceron (2010) (2007 in UK)
• Sapphique (January 2011) (2008 in UK)

• 1995, The Candle Man won Best English-Language Book at the Tir na n-Og Awards
• 2003, The Oracle shortlisted for the Whitbread Children's Book Award
• 2003, The Oracle nominated for the Bram Stoker Award for Best Work for Young Readers
• 2007, Corbenic won the Mythopoeic Fantasy Award for Children's Literature