The 1929 Grand Prix season was another interim year, where most races were run to Formula Libre rules due to a lack of regulations from the AIACR that would be popular for race organisers and manufacturers. This blurred the line between racing cars and sports cars with both competing in the same races. Bugatti won the major international races, with their drivers Louis Chiron and "W Williams". The Italian Championship proved very competitive, attracting many top drivers. There it was Alfa Romeo, using their 4-year old P2 model that claimed more victories, than their main competition coming from Bugatti and Maserati.

William Charles Frederick Grover-Williams, also known as "W Williams", was a British Grand Prix motor racing driver. He is best known for winning the first Monaco Grand Prix.