Arnold Alois Schwarzenegger (born July 30, 1947) is an Austrian and American actor, businessman, former politician, and former professional bodybuilder, known for his roles in high-profile action films. He served as the 38th governor of California from 2003 to 2011.

Schwarzenegger began lifting weights at age 15 and won the Mr. Universe title aged 20, and subsequently the Mr. Olympia title seven times. He is tied with Phil Heath for the joint-second number of all-time Mr. Olympia wins, behind Ronnie Coleman and Lee Haney, who are joint-first with eight wins each. Nicknamed the "Austrian Oak" in his bodybuilding days, he is regarded as one of the greatest bodybuilders of all time. He has written books and articles about bodybuilding, including the autobiographical Arnold: The Education of a Bodybuilder (1977) and The New Encyclopedia of Modern Bodybuilding (1998). The Arnold Sports Festival, the second-most prestigious bodybuilding event after the Mr. Olympia competition, is named after him. He appeared in the bodybuilding documentary Pumping Iron (1977), which set him on his way to a career in films.

After retiring from bodybuilding, Schwarzenegger gained worldwide fame as a Hollywood action star, with his breakthrough in the sword and sorcery epic Conan the Barbarian (1982), a box-office success with a sequel in 1984. After playing the title character in the science fiction film The Terminator (1984), he starred in Terminator 2: Judgment Day (1991) and three other sequels from 2003 to 2019. His other successful action films included Commando (1985), The Running Man (1987), Predator (1987), Total Recall (1990), and True Lies (1994), in addition to comedy films such as Twins (1988), Kindergarten Cop (1990) and Jingle All the Way (1996). At the height of his career, Schwarzenegger was known for his rivalry with Sylvester Stallone. Films in which he has appeared have grossed over $5.4 billion worldwide. He is the founder of the film production company Oak Productions.

As a registered member of the Republican Party, Schwarzenegger chaired the President's Council on Physical Fitness and Sports during most of the George H. W. Bush administration. In 2003, he was elected governor of California in a special recall election to replace Gray Davis, the governor at the time. He received 48.6 percent of the vote, 17 points ahead of the runner-up, Cruz Bustamante of the Democratic Party. He was sworn in on November 17 to serve the remainder of Davis' term, and was reelected in the 2006 gubernatorial election with an increased vote share of 55.9 percent to serve a full term. In 2011, he reached his term limit as governor and returned to acting. As of 2025, Schwarzenegger and Steve Poizner are the last Republicans to win or hold statewide office in California, having both won their respective elections in 2006.

Arnold Alois Schwarzenegger was born in Thal, Styria, on July 30, 1947, the second son of Gustav Schwarzenegger and his wife Aurelia (née Jadrny; 1922–1998). Gustav was the local chief of police, and, after the Anschluss in 1938, joined the Nazi Party and in 1939 the Sturmabteilung (SA). In World War II, Gustav served as a military policeman in the invasions of Poland, France and the Soviet Union, including the siege of Leningrad, rising to the title of hauptfeldwebel. He was wounded in the Battle of Stalingrad, and was discharged in 1943 following a bout of malaria. According to Holocaust scholar Michael Berenbaum, Gustav Schwarzenegger served "in theaters of the war where atrocities were committed. But there is no way to know from the documents whether he played a role." Gustav's background received wide press attention during the 2003 California gubernatorial recall election in which Schwarzenegger was elected.

Gustav married Aurelia on October 20, 1945; he was 38 and she was 23. According to Schwarzenegger, his parents were very strict: "Back then in Austria it was a very different world ... if we did something bad or we disobeyed our parents, the rod was not spared." He grew up in a Catholic family. Gustav preferred his elder son, Meinhard, over Arnold. His favoritism was "strong and blatant", which stemmed from unfounded suspicion that Arnold was not his biological child. Schwarzenegger says that his earliest childhood memory is of climbing into his parents' bed during a bad thunder-and-lightning storm and cuddling between his mother and father. He has said, however, that his father had "no patience for listening or understanding your problems". He had a good relationship with his mother, with whom he kept in touch until her death.

In an interview with Fortune in 2004, Schwarzenegger told how he suffered what "would now be called child abuse" at the hands of his father: "My hair was pulled. I was hit with belts. So was the kid next door. It was just the way it was. Many of the children I've seen were broken by their parents, which was the German-Austrian mentality. They didn't want to create an individual. It was all about conforming. I was one who did not conform, and whose will could not be broken. Therefore, I became a rebel. Every time I got hit, and every time someone said, 'You can't do this,' I said, 'This is not going to be for much longer because I'm going to move out of here. I want to be rich. I want to be somebody.'"

At school, Schwarzenegger was reportedly academically average but stood out for his "cheerful, good-humored, and exuberant" character. He struggled with reading and was later diagnosed as being dyslexic. Money was a problem in their household; Schwarzenegger recalled that one of the highlights of his youth was when the family bought a refrigerator. His father Gustav was an athlete, and wished for his sons to become champions in Bavarian curling. Influenced by his father, Schwarzenegger played several sports as a boy.