The Keys to the Kingdom is a fantasy-adventure book series written by Garth Nix, comprising seven books published between 2003 and 2010. The series chronicles the adventures of a boy named Arthur, who becomes involved with a magical world called the 'House'; he is on a quest to take back the House from seven antagonistic 'Trustees'.

Garth Richard Nix is an Australian writer who specialises in children's and young adult fantasy novels, notably the Old Kingdom, Seventh Tower and Keys to the Kingdom series. He has frequently been asked if his name is a pseudonym, to which he has responded, "I guess people ask me because it sounds like the perfect name for a writer of fantasy. However, it is my real name."