Katherine Legge competed in the 2005 Toyota Atlantic Championship, where she won the series opener at Long Beach in her first career Toyota Atlantic start.
In doing so, “Kat” became the first woman to win a major open-wheel race in North America. Legge went on to win two more races to finish the season third in the championship with a total of three wins and five podiums.
She also received the Toyota Atlantic BBS Rising Star 2005 Award.
Prior to the Toyota Atlantic series, she raced in several developmental open-wheel series in Britain, including Formula 3, Formula Renault, and Formula Ford.
She was the first woman to receive the BRDC's "Rising Star" accolade and the 2005 RACER Magazine "Most Promising Road Racer of The Year" award.
Driving for PKV Racing in the 2006 Champ Car season, she became the first woman to lead a lap in series history.
She finished sixth at Milwaukee and eighth at Cleveland finishing third in the chase for Rookie of the Year honors.
Legge switched to Dale Coyne Racing in 2007, and a her best result in the series was a sixth place, twice.
For 2008, she raced for Audi in the DTM series and impressed in the older car enough to be assigned one of the desirable seats in the newer chassis for 2009.