Jenny Nimmo was born in Windsor, Berkshire, England. She was an only child, and her father died when she was five. According to a short article by the American publisher of the series, Nimmo was a voracious reader as a child, which led her to write her own stories to share with friends.

After working for a time in theater, Nimmo worked for several years with the BBC. Part of that time was spent adapting other writers' stories for television. Her first book, The Bronze Trumpeter, began life as a television script.

In 1974, she married David Wynn Millward, an artist and illustrator. She has three children and currently lives in Wales, sharing her time between writing and helping her husband with a summer art school.

• The Bronze Trumpeter (1974)
• The Magician Trilogy
• The Snow Spider (1986)
• Emlyn's Moon (1987)
• The Chestnut Soldier (1989)

• Ultramarine (1990)
• Rainbow and Mr. Zed (1992); sequel to Ultramarine
• The Stone Mouse (1993)
• The Witches and the Singing Mice (1993)
• Griffin's Castle (1994)
• The Owl Tree (1997)
• The Rinaldi Ring (1999)
• Toby in the Dark (1999)
• Milo's Wolves (2001)

• Children of the Red King series
• Midnight for Charlie Bone (2002)
• The Time Twister (2003) (US title: Charlie Bone and the Time Twister)
• The Blue Boa (2004) (US title: Charlie Bone and the Invisible Boy)
• The Castle of Mirrors (2005) (US title: Charlie Bone and the Castle of Mirrors)
• Charlie Bone and the Hidden King (2006)
• Charlie Bone and the Wilderness Wolf (2007) (US title: Charlie Bone and the Beast)
• Charlie Bone and the Shadow of Badlock (2008) (US title: Charlie Bone and the Shadow)
• Charlie Bone and the Red Knight (Sept 2009) (US May 2010)