This is a list of the world's record-breaking top speeds achieved by a street-legal production car (as opposed to concept cars or modified cars). For the purposes of this list eligible cars are defined in the lists rules. This list uses the same definition as the List of automotive superlatives for the sake of consistency and because the term production car is otherwise undefined. The Benz Velo, as the first production car, is an exception.
Comparing claimed speeds of the fastest production cars in the world, especially in historical cases, is difficult as there is no standardized method for determining the top speed and no central authority to verify any such claims. Examples of the difficulties faced were shown up in the dispute between Bugatti and Hennessey over which car was the world's fastest.
The current Guinness World Records title holder, the Bugatti Veyron Super Sport, was certified for the average top speed achieved on a two-way run, registering 431 km/h (268 mph). Bugatti made 5 Veyrons named the World Record Edition out of the initial production run of 30 Super Sports, all of which would be able to achieve this speed if the limiter was removed. Bugatti did not sell any with the limiter removed. Initially, when challenged by Hennessey, Guinness decided the Bugatti was ineligible because the test car was deemed as being modified. Bugatti sought a review of the decision and Guinness, after a review by a panel of experts, considered removing the limiter was not a modification and thereby making the car eligible for their publication.
In 2014, a Hennessey Venom GT was recorded as exceeding 270.49 mph (435.31 km/h), but as the run was in one direction only, and only 12 cars (+ 1 prototype) were ever made and thus it does not qualify under the Guinness Book of Records or this list's criteria as the world's fastest production car. Guinness accepted it as production car, however.
Because of the inconsistencies with the various definitions of production cars, dubious claims by manufacturers and self-interest groups, and inconsistent or changing application of the definitions this list has a defined set of requirements. For further explanation of how these were arrived at see the above link.