* Framed (1998)
* Millions (1999) (Whitbread Award winner and Carnegie Medal shortlist)
* The Astounding Broccoli Boy (2004)
* Cosmic (2008)
* The Unforgotten Coat (2011)
* Noah Barleywater Runs Away (2015)
* Sputnik's Guide to Life on Earth (2018)
* The Girl Who Became a Tree (2021)
Books for older children and young adults
* Millions (2006) (film novelization)
* The Graveyard Book by Neil Gaiman (2008) (audiobook narrator)
* Runaway Robot (2011)
* Go and Come Back (2013)
* The 24-Hour War (2016)
* The Amazing Maurice and His Educated Rodents by Terry Pratchett (2007) (audiobook narrator)
* The Witches by Roald Dahl (2020) (audiobook narrator)
Short stories
* "Sputnik 1" (2018)
* "Noah's Ark" (2020)
* "The Girl Who Became a Tree" (2021)
Non-fiction
* The Making of Millions (2004) (with Chris van Allsburg)
* The Astounding Broccoli Boy: The Science Behind the Story (2005)
* Cosmic: The Science Behind the Story (2009)
* The Unforgotten Coat: The Science Behind the Story (2012)
* Noah Barleywater Runs Away: The Science Behind the Story (2016)
* Sputnik's Guide to Life on Earth: The Science Behind the Story (2019)
* The Girl Who Became a Tree: The Science Behind the Story (2022)