Thomas Mario "Tommy" Haas (born April 3, 1978) is a German professional tennis player who reached a career-high ranking of World No.2 on May 13, 2002.

Tommy is an all-court all-around player with a very versatile style. He has solid groundstrokes off both wings and he is also a solid volleyer with the ability to transition to the net easily. Unlike many top pro's, he doesn't specialize in any particular playing style but rather adapts his game to counter his opponent's style. Tommy's best weapon is his powerful single-handed backhand which is among the best in the game. His forehand is also a major weapon. His serve is considered average and his weakness as a player has more to do with inconsistency and mental stability rather than anything technical. Often Tommy's biggest enemy in a match is himself whenever he loses control of his temper.

Born in Hamburg, Germany to Brigitte and Peter Haas, Haas started playing his own version of tennis when he was two years old, by using a wooden plank to hit balls against the wall or into his father's hands. When his father noticed his talents, he started bringing Haas to work, as he happened to be a tennis coach.