Danny King was born in Slough, Berkshire. He is the second son of Michael James King, a bricklayer, and Dorothy May King. He and his two brothers, Ralph and Robin, lived on the Britwell Estate until 1979, when they moved to Yateley, Hampshire. He attended Yateley School but failed to gain any qualifications before leaving at the age of 16. He stacked shelves for a short stint in the Yateley branch of Somerfield (then Gateway), before working on various building sites as a hod carrier.
In 1991 he took an Access course at Farnborough College of Technology, which helped him land a place at The London College of Printing studying journalism. Between 1993 and 2002 he worked on various magazine titles, eventually becoming Editor of the Paul Raymond Publications title Mayfair . He lost this job after just one year and now writes full-time.
In the late 1980s, he was arrested several times and convicted of burglary at Winchester Crown Court and car theft at Camberley Magistrates Court. It is largely due to receiving these convictions that he sites as his reasons for giving education a second go.
He married Jeannette Susan Crockett in March 2007 and they live in Chichester, West Sussex with their son, Charles Stewart Milo King (b. 09.04.08) and daughter, Katherine Marie Crockett King (b. 23.03.10).
He adapted his fourth book, The Pornographer Diaries, for the stage. It was produced by Have a Word Productions (Kate McCarthy) and played at the C venues during the 2007 Edinburgh Festival from August 1-27, starring Gary Beadle, Jessica Harris and David Swire.
The Hitman Diaries was translated (Killlera Dienasgr?mata) and adapted for the stage by J. J. Jillinger and performed by the Liep?ja Teatris (Theatre) Company in Latvia in 2007. The Literary Director was Edite Tisheizere.