Thomas Mario Haas is a German former professional tennis player. He competed on the ATP Tour from 1996 to 2017. After breaking into the world top 100 in 1997 and reaching a career-high singles ranking of world No. 2 in May 2002, his career was interrupted by injuries: Haas 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 was absent between February 2010 and June 2011, but returned to world No. 11 in 2013 by reaching the quarterfinals at the French Open for the first time. Haas reached the semifinals of the Australian Open three times, and in Wimbledon once. He reached the quarterfinal stage of each of the major events. He won 15 career titles in singles, including a Masters title at the 2001 Stuttgart Masters, and a silver medal from the 2000 Summer Olympics.

Russia's Yevgeny Kafelnikov defeated Germany's Tommy Haas in the final, 7–6(7–4), 3–6, 6–2, 4–6, 6–3 to win the gold medal in Men's Singles tennis at the 2000 Summer Olympics. In the bronze-medal match, France's Arnaud Di Pasquale defeated Switzerland's Roger Federer, 7–6(7–5), 6–7(7–9), 6–3. It was Russia's first medal in the event as an independent country. France and Germany won their first medals in the event since 1924 and 1912, respectively.