Guy Stuart Ritchie (born 10 September 1968) is an English film director, producer and screenwriter. His work includes British gangster films and the Sherlock Holmes films starring Robert Downey Jr.

Ritchie left school at the age of 15. He worked in entry-level jobs in the film industry before directing television commercials. In 1995, he directed a short film, The Hard Case, followed by the crime comedy Lock, Stock and Two Smoking Barrels(1998), his feature-length directorial debut. He gained recognition with his second film, Snatch (2000), which was found to be critical and commercially successful. Following Snatch, Ritchie directed Swept Away (2002), a critically panned box-office bomb starring Madonna, to whom Ritchie was married between 2000 and 2008. He went on to direct Revolver (2005) and RocknRolla (2008), which were less successful and received mixed reviews. In 2009 and 2011, he directed the box-office hits Sherlock Holmes and its sequel, Sherlock Holmes: A Game of Shadows. The former was nominated for Academy Awards in Best Original Score and Best Art Direction.