Arnold Alois Schwarzenegger (born July 30, 1947) is an Austrian-American actor, film producer, businessman, former bodybuilder and politician who served as the 38th governor of California (2003-2011). As of 2022, he is the most recent Republican governor of California. Time magazine named Schwarzenegger one of the 100 most influential people in the world in 2004 and 2007. He also served as Chairman of the President's Council on Physical Fitness and Sports (1990-1993).

He began weight training at 15. He was awarded the title of Mr. Universe at age 20 and went on to win the Mr. Olympia contest a total of seven times. He appeared in the bodybuilding documentary Pumping Iron (1977). The Arnold Sports Festival, considered the second-most important bodybuilding event after Mr. Olympia, is named after him. He has remained a prominent presence in the sport of bodybuilding and has written several books and numerous articles on the sport.

He wanted to move from bodybuilding into acting, finally achieving it when he played the title role in Hercules in New York (1970). Credited under the stage name "Arnold Strong", his accent in the film was so thick that his lines were dubbed after production. His second film role was as a mob hitman in The Long Goodbye (1973), followed by a more significant part in the film Stay Hungry (1976), for which he won the Golden Globe Award for New Star of the Year – Actor.

In 1977, he appeared in an episode of the ABC sitcom The San Pedro Beach Bums and the ABC police procedural The Streets of San Francisco. He auditioned for the title role of The Incredible Hulk, but did not win the role because of his height. He appeared in the 1979 comedy The Villain. In 1980, he starred in a biographical film of the 1950s actress Jayne Mansfield as her husband, Mickey Hargitay.

He gained worldwide fame as a Hollywood action star with his breakthrough starring role in the epic Conan the Barbarian (1982) and its sequel in 1984. After playing the title role in the sci-fi action film The Terminator (1984), he starred in its' sequels Terminator 2: Judgment Day (1991), Terminator 3: Rise of the Machine's (2003), Terminator Genisys (2015), and Terminator: Dark Fate (2019). His other action films include Commando (1985), The Running Man (1987), Predator (1987), Red Heat (1988), Total Recall (1990), and True Lies (1994). His comedy films include Twins (1988), Kindergarten Cop (1990), Junior (1994), and Jingle All the Way (1996).

After leaving the governor's office, he resumed his acting career. He starred in The Expendables 2 (2012), The Last Stand (2013), his first leading role in 10 years, Escape Plan (2013), Sabotage (2014) and returned as Trench Mauser in The Expendables 3 (2014). He then starred in the Terminator sequels Terminator Genisys (2015) and Terminator: Dark Fate (2019). He was slated to reprise his role as Conan in The Legend of Conan, later renamed Conan the Conqueror; however, in April 2017, producer Chris Morgan stated that Universal had dropped the project, although there was a possibility of a TV show. 

He was nicknamed the "Austrian Oak" and the "Styrian Oak" in his bodybuilding days, "Arnie" and "Schwarz" during his acting career and the "Governator" (a portmanteau of "Governor" and "Terminator"). He is the founder of the film production company Oak Productions.