Thomas Mario "Tommy" Haas is a German professional tennis player. He has competed on the ATP Tour since 1996. After breaking into the world top 100 in 1997, and reaching a career-high singles ranking of World No. 2 in May 2002, Haas's career was interrupted by injuries: he has twice dropped out of the world rankings due to being unable to play for twelve months. His first period of injury saw him miss the whole of the 2003 season, and he did not return to the world's top 10 until 2007. He also missed over a year's tennis between February 2010 and June 2011, but has since returned to play on the tour. He returned to World No. 11 in 2013 after reaching the quarterfinals at the French Open for the first time in his career.
Although Haas has never won a Grand Slam tournament, he has reached the semifinals of the Australian Open three times, and Wimbledon once. He is one of few players to have reached the quarterfinal stage of each of the Grand Slams. He has won 15 career titles in singles, including one Masters tournament, and has a silver medal from the 2000 Summer Olympics.