Docx was born in 1972, and educated at St Bede's College, Manchester and Christ's College, Cambridge. At Christ's he read English Literature and was also president of the Junior Common Room.

Docx has worked on newspapers and in television but is now primarily a writer of fiction. His first novel, The Calligrapher, was published by 4th Estate in 2003, and was well-received by many critics. For example, The Boston Globe described it as "...a delight, a witty, deftly written, honest comedy of manners".

Docx's second novel Self Help was published in July 2007 by Picador, and was longlisted for the 2007 Man Booker Prize. Docx won the 2007 Geoffrey Faber Memorial Prize for the novel, which was published as Pravda in the United States.

In 2008 his short story A Good Man was published in the 'Picador Shots' series.