TSG 1899 Hoffenheim is a German football club based in Hoffenheim, a suburb of Sinsheim, Baden-Württemberg. In 2007, the club decided to adopt the use of the short form name 1899 Hoffenheim in place of the traditional TSG Hoffenheim.

The modern-day club was formed in 1945, when gymnastics club Turnverein Hoffenheim (founded July 1, 1899) and football club Fußballverein Hoffenheim (founded 1921) merged. At the beginning of the 1990s, the club was an obscure local amateur side playing in the eighth division Baden-Württemberg A-Liga. They steadily improved and by 1996 were competing in the Verbandsliga Nordbaden (V).
    Around 1990, alumnus Dietmar Hopp returned to the club of his youth, not as a player or manager, but as financial backer. Hopp was the co-founder of software firm SAP and he put some of his money into the club. His contributions generated almost immediate results: in 2000 Hoffenheim finished first in the Verbandsliga and was promoted to the fourth-division Oberliga Baden-Württemberg. Another first place finish moved the club up to the Regionalliga Süd (III) for the 2001–02 season. They finished 13th in their first season in the Regionalliga, but improved significantly the next year, earning a fifth place result.
    Hoffenheim earned fifth and seventh place finishes in the next two seasons, before improving to fourth in 2005–06 to earn their best result to date. The club made its first German Cup appearance in the 2003–04 competition and performed well, advancing to the quarterfinals by eliminating 2. Bundesliga sides Eintracht Trier and Karlsruher SC and Bundesliga club Bayer Leverkusen before being put out themselves by another 2. Bundesliga side, VfB Lübeck.
    Negotiations to merge TSG Hoffenheim, FC Astoria Walldorf, and SV Sandhausen to create FC Heidelberg 06 in 2005 were abandoned due to the resistance of the latter two clubs, and the failure to agree on whether the new side's stadium should be located in Heidelberg or Eppelheim. Team owner Hopp clearly preferred Heidelberg, but could not overcome the resistance of local firm Wild, which had already reserved the site of the planned stadium for its new production facilities.
    In 2006, the club sought to improve its squad and technical staff by bringing in players with several years of Bundesliga experience, most notably Jochen Seitz and Tomislav Marić, and by signing Ralf Rangnick, former manager of Bundesliga teams SSV Ulm 1846, VfB Stuttgart, Hannover 96, and Schalke 04, to a five-year contract. The investment paid off in the 2006–07 season with the club's promotion to the 2. Bundesliga after finishing 2nd in Regionalliga Süd.
    Remarkably, the club spent only a single season in the 2. Bundesliga, where they finished in 2nd place and received automatic promotion. The 2008–2009 season is Hoffenheim's first in the German top division where they are in first place after 14 weeks.