Sommer was born into a wealthy Sedan, France carpet making family. His father, Roger, broke the Wright Brothers record for the longest flight in 1909. It was not until 1931 that Raymond started to display daredevil tendencies of his own, entering motor races in a privateer Chrysler Imperial. The following year, he won the 24 hours of Le Mans , despite having to drive over 20 hours solo after his teammate Luigi Chinetti retired ill. During the 1930s, Sommer was to dominate the French endurance classic, winning again in 1933 driving an Alfa Romeo alongside the greatest driver of the time, Tazio Nuvolari. He also led every race up until 1938, only to suffer a mechanical failure, once when 12 laps in the lead.
However, his tendency to run in privately entered cars did him no favours on the Grand Prix scene, winning just one major international race, the 1936 French Grand Prix. At the time the French Bugatti team and the German manufacturers Mercedes-Benz and Auto Union, were the dominant force in GP racing, with Hitler unwilling to see drivers from non-fascist countries in the cars. Sommer turned to sports cars once more, winning the Spa 24 Hours. More wins came his way including at the "Marseilles Three Hours" at Miramas and the Grand Prix de Tunisie until the outbreak of World War II, where he played an active part in the French Resistance movement.
Following the war, Sommer quickly returned to winning ways, and at the 1947 Turin Grand Prix in Valentino Park he won the first ever Grand Prix for Enzo Ferrari as an independent constructor. The following season, Sommer switched from the Ferrari team, again for a privately owned car, this time a Talbot Lago. In 1950, the F1 World Championship began and Sommer drove in five Grand Prix races for Talbot and BRM, retiring each time after his car failed.
In September 1950, he entered the Haute-Garonne Grand Prix in Cadours, France where the steering failed on his 1100 cc Cooper and the car overturned at a corner. Raymond Sommer was instantly killed, his traditional canvas helmet proving to be no use at all.