Leonard Bailey (25 July 1926 – 23 June 1997) was a British automobile designer.
Leonard Bailey became an apprentice at Austin at Longbridge in 1942 which at that time were building Short Stirlings for the Royal Air Force of World War II. Building up his experience at Daimler and Rover in Coventry before moving back to Austin which became part of British Motor Corporation (BMC) in 1952 to work in the engine department. He moved to the USA and by mid 1956 was working at American Motors working on that companies first in house V8 after a deal to buy Packard V8 became too expensive. In 1958 he move to Ford head office at Dearborn, Michigan working in their engine department but was moved to the Experimental Department by Roy Lunn. He worked on prototypes under him including the development of Ford turbine cars and he was part of the design team that built a two-seat Ford Mustang I in 1962
With Ford taking a more pro active motor spot stance in 1963 he was moved back to England to a position of chief draftsman as part of the design team for Fords new GT40 sport car with Ford Advanced Vehicles Ltd FAV department in Slough. Lola had completed a Ford-powered, mid-engined sports car in 1963 this would form the basis for the Ford assault on winning Le-Mans, the new project was to be based at FAV . They would have responsible for the engineering of the chassis, body and construction of the cars. Eric Broadley was initially responsible for the overall design, but Len Bailey later took care of the chassis reengineering it from Aluminum to Steel for more durability in the 24 hour Race. Ford felt it was also necessary to cope with the added weight of the more powerful all aluminum, dry-sump Ford Fairlane . By 1966 he was based at Alan Mann Racing base in Byfleet Surry although still employed by Ford of Europe. Early in 1966 several chassis were shipped to United States to be fitted with the larger, more powerful engine in preparation for Fords third attempt at taking that elusive Le Mans win. These seven litre cars are we now referred to as Mark IIs No fewer than eight GT40 Mark IIs were race prepared for the 1966 24 Hours of Le Mans. Although entered by three different privateer teams All Factory Ferraris had retired by 17 hours of the race, as had nine of the Fords, but three held together long enough to score an historic photo staged 1–2-3 finish