Andre Agassi is a former professional tennis player from the United States. He is considered one of the greatest tennis players of all time, having won eight Grand Slam singles titles and an Olympic gold medal. Agassi was the first male player to win all four Grand Slam tournaments on three different surfaces. He was also the first male player to win the Career Grand Slam and the ATP Tour World Championships. Agassi retired from professional tennis in 2006 and is now a philanthropist and businessman.