In an agreement worth £1.9 million at showroom prices, the 3.0 dCi Privilege models will be added to National's UK network of 130 branches.
Aimed at corporate clients, most of the cars will be based at airport branches, and National said the car is prompting positive feedback from clients.
Stephen Deakin, fleet director of National Car Rental, said: 'The Vel Satis is a radical departure from the traditional executive car. It has a completely fresh look, which is distinctly different from other cars in the executive sector, and supplements our fleet well.
'The Vel Satis offers style, a high level of performance, is exceedingly well equipped and extremely comfortable, particularly for long distance journeys.'
John Darke, rental manager for Renault UK, said: 'We are delighted National felt it important to ensure its corporate customers have the option to take the Vel Satis and that the car has already been so well received.'