Simon Francis Mann (born 26 June 1952) is a security expert, mercenary, former British Army officer, and South African citizen who is currently serving a 34-year prison sentence in Equatorial Guinea for his role in a failed coup d'etat in 2004.

Mann was extradited to Equatorial Guinea on 1 February 2008, having been accused of planning a coup d'etat to overthrow the government by leading a mercenary force into the capital Malabo in an effort to kidnap or kill President Teodoro Obiang Nguema Mbasogo. Charges in South Africa of aiding a coup in a foreign country were dropped on 23 February 2007, but the charges remained in Equatorial Guinea, where he had been convicted in absentia in November 2004. He lost an extradition hearing to Equatorial Guinea after serving three years of a four-year prison sentence in Zimbabwe for the same crimes and being released early on good behavior. On the arrival of Mann in Equatorial Guinea for his trial in Malabo, public Prosecutor Jose Olo Obono said that Mann would face three charges - crimes against the head of state, crimes against the government, and crimes against the peace and independence of the state. On July 7, 2008, Mann was sentenced to 34 years and four months in prison by a court in Equatorial Guinea.

Simon Mann's father, George Mann, captained the England cricket team in the late 1940s and was heir to the Watney Mann brewing empire that closed in 1979, having been acquired by Grand Metropolitan plc (which, in turn, became Diageo plc on its merger with Guinness plc in 1997). George's father (Simon's grandfather) Frank Mann, also captained the England cricket team in 1922/23. After leaving Eton College, Simon Mann trained as an officer at Sandhurst and joined the Scots Guards. He later became a member of the SAS and served in Cyprus, Germany, Norway and Northern Ireland before leaving the forces in 1985. He was re-called to action from the reserves for the Gulf War.