Mouton debuted in rallying as a co-driver but quickly moved to the driver's seat, steering an Alpine-Renault A110 in national rallies. In 1975, she competed in circuit racing and won the two-litre prototype class in the 24 Hours of Le Mans. After being signed by Fiat France for 1977, Mouton finished runner-up to Bernard Darniche in the European Rally Championship. She went on to win the 1978 Tour de France Automobile and record consistent results in her home events in the WRC; the Tour de Corse and the Monte Carlo Rally. For 1981, Audi Sport signed Mouton to partner Hannu Mikkola. In her first year with the Audi Quattro, she took a surprise victory at the Rallye Sanremo.