Olivier Gruner (French: [ɔlivje ɡʁyne] (listen); born August 2, 1960), also named O.G, Оливье Грюнер in Russian, and 奥利弗·古鲁内尔 in Chinese, is a French former naval commando, actor, director, producer, screenwriter, martial artist, and pilot. Born in Paris, France, he moved to the United States in 1988. His career began in 1987 at the Cannes Film Festival, France, where he was discovered.He has since appeared in over 40 films and four television series and is best known for his martial art and science fiction action films. Gruner is regarded as an "action hero" due to his portrayal of Alex Raine in Nemesis (1992), Lt. Sean Lambert in the Interceptor Force franchise (2000–2002), and of Dirk Longstreet in The Circuit franchise (2001-2006).His credits also include urban action movie Angel Town (1989), Automatic (1994), Savate (1995), Mercenary (1996), The white Pony (1999), Kumite (2000), Blizhniy Boy: The Ultimate Fighter (2007), Lost Warrior: Left Behind (2008), One Night (2010), and Beyond the Game (2016).
As a martial artist, Gruner was a full-time kickboxer in France for 8 years from 1981 to 1988. He became France middleweight champion, then middleweight full-contact kickboxing world champion in 1985, and again middleweight kickboxing world champion in 1986.