Reginald Harold Haslam "Reg" Parnell (2 July 1911 – 7 January 1964) was a racing driver and team manager from Derby, England. He participated in seven Formula One World Championship Grands Prix, achieving one podium, and scoring a total of nine championship points.
Parnell who, as both a driver and a team manager, had a considerable influence on post-war British motorsport until his premature death in 1964. Parnell raced at Brooklands and was banned following an accident with Kay Petre which ended her racing career. Before the war he brought up racing cars. Once the hostilities had ceased he sold them to form the basis of post-war racing entries. He later raced a whole host of cars before turning to management and taking Aston Martin into Formula 1. Parnell went on to run the Yeoman Credit Racing team with the help of his son Tim who later raced in Formula 1 himself.
Parnell came from a family which ran a garage business in Derby. In 1933, he was a spectator when Donington Park held its first motor race, and he decided to try the sport. By 1935, he bought an old 2-litre Bugatti single-seater for just £25. It broke its rear axle in the paddock at its first meeting, but buying spare parts for the Bugatti was way too expensive, so this was soon and replaced with a MG Magnette K3. Parnell had secured wins at both Brooklands and Donington Park, but in 1937 he lost his license following a practice accident for the 500 Mile race, at Brooklands. He misjudged an overtaking move on Kay Petre, when he lost control of the MG, crashing into her Austin 7 from behind, causing it to roll. She crashed badly and was seriously injured. She never raced competitively again. Although she put the incident down to ‘bad luck’, the RAC revoked Parnell’s racing license for two years. This meant that he was unable to race.