Thomas Biagi began his racing career end of the 1980s in karting. About the Formula Alfa Boxer he came in 1994 in the Italian Formula 3000 Championship, which he claimed two victories ended 1995 as the fifth overall. From the end of season 1995-1998, the youngster competed in the International Formula 3000 championship without achieving this significant success. At his debut race in Magny Cours 1995 he had a collision with Marco Campos, in which the Brazilian was killed.
1999 Biagi returned back to the Italian Formula 3000 Championship, where he was 2001 championship runner-up.
Was far more successful and is the Italian sports car racing. In 2003, he won jointly with Matteo Bobbi the GT class of the FIA GT Championship in a Ferrari 550 Maranello BMS Scuderia Italia. In 2007 he repeated this success when he won on a Maserati MC12 drivers' title in the GT1 class. In 2008 he drove a Ferrari F430 in the GT2 class for AF Corse. In 2009, he launched now in both the FIA GT Championship and the Le Mans Series. While he was moving in the LMS throughout the year a Le Mans prototype racing team Racing Box, changed his race team at the half in the FIA GT Matech and Luc Alphand Aventures between. In addition, he started at the end of the 6-hour race at Vallelunga in Lola Racing Box, which he won with Filippo Francioni and Edoardo Piscopo.
2012 won Biagi as a private driver along with his teammate Stefano Colombo, the Italian GT Championship. At the same time, he won the traditional BMW Sports Trophy, as a reward for this he was given the opportunity for a test in the BMW M3 DTM.