After beginning her career in karting, she moved to cars in 2004 in Formule Renault 2.0 Suisse and finished 6th. The next year she moved to the more highly regarded German championship for the same cars and finished 12th. In 2006 she moved up to the Formel 3 Cup, finishing in 9th place and winning the pole position at EuroSpeedway Lausitz. The following year she drove in the Formula Three Euroseries for British team Manor Motorsport racing a Dallara-Mercedes, but despite participating in all 20 races, failed to score points and was not classified in the season standings.
In 2008, Cyndie Allemann signed to race in Firestone Indy Lights Series for American Spirit Racing. She would go on to finish 14th in the final points standings with her best result being a 4th place in the second race at the Mid-Ohio Sports Course in July.
For the 2010 season she teamed up with Natacha Gachnang and race for the Swiss Matech team in a GT1 class Ford GT. Primarily racing in the FIA GT1 World Championship she also raced in the 2010 24 Hours of Le Mans
