Andre Kirk Agassi (/ˈɑːndreɪ ˈæɡəsi/ AHND-ray AG-ə-see; born April 29, 1970) is an American retired professional tennis player and former World No. 1 who was one of the sport's most dominant players from the early 1990s to the mid-2000s. Generally considered by critics and fellow players to be one of the greatest tennis players of all time, Agassi has been called the greatest service returner ever to play the game. Described by the BBC upon his retirement as "perhaps the biggest worldwide star in the sport's history", Agassi compiled performances that, along with his unorthodox apparel and attitude, saw him cited as one of the most charismatic players in history. As a result, he is credited for helping to revive the popularity of tennis during the 1990s.
In singles tennis, Agassi is an eight-time Grand Slam champion and a 1996 Olympic gold medalist, as well as finishing runner-up in seven other Grand Slam tournaments. During the Open Era, Agassi was the first male player to win four Australian Open titles, a record that was later surpassed by Novak Djokovic when he won his fifth title in 2015, and then by Roger Federer in 2017. Agassi is one of five male singles players to achieve the Career Grand Slam in the Open Era and one of eight in history, the first of two to achieve the Career Golden Slam (Career Grand Slam and Olympic Gold Medal, the other being Rafael Nadal), and the only man to win the Career Golden Slam and the ATP Tour World Championships (won in 1990): a distinction dubbed as a "Career Super Slam" by Sports Illustrated.