Thomas Johansson (born March 24, 1975, in Linköping, Sweden) is a professional tennis player. He joined the pro tour for the first time in 1993 and has won 9 top-level singles titles and 1 doubles title, including the 1999 Canada Masters (df. Yevgeny Kafelnikov) and the 2002 Australian Open Grand Slam championship, which he unexpectedly won (on his 25th attempt at winning a Grand Slam title) after defeating his heavily favored opponent, Marat Safin, in four sets, 3-6 6-4 6-4 7-6. Johansson became the first Swedish player to win a Slam since Stefan Edberg won the 1992 U.S. Open title, and the first Swede to claim the Australian since Mats Wilander in 1988.

Johansson would later reach his career high ranking of World No. 7 in June of 2002 and finish the season with a career best year-end ranking of 14th in the ATP Champions Race, a feat he would later repeat in 2005.

A knee injury robbed Johansson of the latter half of the 2002 season and all of 2003, and Johansson was therefore unable to compete on the tour full-time until 2004. In 2005, he became the first Swedish player to reach the semifinals at Wimbledon since Stefan Edberg in 1993, losing to Andy Roddick in a tightly contested four set match, 7-6 2-6 6-7 6-7. At the end of the season, Johansson won his 9th, and until now, last ATP tournament in St. Petersburg, defeating Nicolas Kiefer 6-4 6-2.

In 2006, the Swede struggled through the season after suffering an eye injury early in the season. The highlights of the season were a 4th RD at the Australian Open (where he lost to Ivan Ljubičić), his first doubles title in Bastaad, Sweden with countryman Jonas Björkman and a final in St. Petersburg (lost to Mario Ancic), where he was the defending champion.

As of October 15th, 2007, he has an 15-13 career Davis Cup record (14-10 in singles) in 14 ties and an 342-273 career overall. He is currently 39th in the ATP rankings.