Antonio Ramón Villaraigosa (pronounced /ˌviːə.raɪˈgoʊsə/; born January 23, 1953), born Antonio Ramón Villar, Jr., is the mayor of Los Angeles, California and third Mexican American to have ever held office in Los Angeles, California. He was elected on May 17, 2005, defeating incumbent mayor James Hahn, and then re-elected for a second term in 2009. Prior to his election as mayor, Villaraigosa was the California State Assemblyman for the 45th District, the Speaker of the California State Assembly, and the Los Angeles City Councilman representing the 14th District.

Before being elected to public office, Villaraigosa was a labor organizer. Villaraigosa served as a national co-chairman of Hillary Rodham Clinton's 2008 Presidential campaign, and as a member of President Barack Obama's Transition Economic Advisory Board.

Born Antonio Ramon Villar in the City Terrace neighborhood of Los Angeles County's eastside, Villaraigosa attended both Catholic and public schools. Villaraigosa's father abandoned the family when he was 5 years old. At the age of 16, a benign tumor in his spinal column briefly paralyzed him from the waist down, curtailing his ability to play sports. His grades plummeted at Cathedral High School. The next year, he was expelled from the Roman Catholic institution after getting into a fight after a football game. He graduated from Roosevelt High School, and with the help of his English teacher Herman Katz, went on to attend East Los Angeles College. Villaraigosa eventually transferred to University of California, Los Angeles (UCLA) where he completed a bachelor's degree in history. Villaraigosa was a leader of MEChA at UCLA. At this time, he went by the name "Tony Villar", but began using his birth name "Antonio" in the 1980s.