Muchamore was born in London; the youngest of four children. Muchamore left school with a D in A Level economics, with the hope of becoming an architect, photographer or writer. After realising training as an architect would require "too much work," and a Saturday job in a camera shop put him off being a photographer, he turned to writing. But, when he found his writing was not to a quality he would have liked, he gave up and secured a job as an office junior for a private investigation firm in 1991. He describes the 90s for him as "pretty dull".

Robert Muchamore started writing the CHERUB books because his nephew in Australia couldn't find any books that he liked reading. He tried to write books that he would have enjoyed reading when he was 12 or 13, a time when he remembers being too old for children's books but not old enough to read adult novels.

The CHERUB series follows the life of a character named James Adams (formerly James Choke), a member of CHERUB, a top-secret branch of the British Secret Service. The organisation recruits orphan children and trains them as intelligence officers. Once qualified, they are used to investigate targets ranging from international terrorists to gang leaders. As children, they are considered innocent by their targets. CHERUB agents start basic training at aged 10. Basic training is a 100 day course that prepares CHERUBs for the dangers they may face during missions. CHERUB agents are then eligible for missions. Once passed basic training, CHERUB agents leave CHERUB when they're aged 18, or in some exceptional cases 19 or 20.

So far Muchamore has written and published eleven CHERUB novels, with another one in production. In 2008 he also released Dark Sun as a World Book Day novella.

The CHERUB series has been sold in more than 20 different countries and has won various awards. Most notably, The Recruit has won 8 literature awards.

Muchamore has written three novels about the beginning of CHERUB entitled Henderson's Boys. The first, The Escape, was released on 5 February 2009 in the UK. It was followed by Eagle Day and Secret Army, released in June 2009 and March 2010 respectively. A fourth, Grey Wolves is set to be released early 2011.

The Henderson's Boys books are set during World War II and follow Charles Henderson, a British secret agent, as he creates the organisation later featured in the CHERUB series. The books feature four children: Marc Kilgour, Paul and Rosie Clarke and PT Bivott.

Home is another book written by Robert Muchamore. It was deemed too violent to be published by a children's publisher and a publisher was never found. The story follows civil war in an unstated central African state, but most probably the Democratic Republic of the Congo. The full book has been released by the author online.

In between writing The Recruit (in which the main character James learns of Cherub and becomes a recruit with his partner Kerry) and Class A, Muchamore wrote a book called Little Criminals. He posted the first two chapters onto the CHERUB series official forum, to see what his fans thought. Unlike Home, Muchamore has not published the rest of the text on his fan forum because he still holds out some hope that it will be published.

CHERUB

• The Recruit (April 2004)
• Class A (October 2004) (also known as The Dealer in USA & The Mission (UK bookclub edition))
• Maximum Security (April 2005)
• The Killing (October 2005)
• Divine Madness (April 2006)
• Man Vs. Beast (October 2006)
• The Fall (March 2007)
• Mad Dogs (October 2007)
• The Sleepwalker (February 2008)
• Dark Sun (World Book Day novella) (March 2008)
• The General (September 2008)
• Brigands MC (September 2009)
• Shadow Wave (September 2010)

Henderson's Boys

• The Escape (February 2009)
• Eagle Day (June 2009)
• Secret Army (February 2010)
• Grey Wolves (February 2011)