The rare 1960 Marcos GT Xylon will go on sale at the Silverstone Classic event on July 26 and 27 with an estimated price tag of between £35,000 and £50,000.
Marcos, founded in 1959 by British Racing Drivers Club member Jem Marsh and the engineer Frank Costin, built just nine Xylons, with the one driven by Sir Jackie the most famous.
The car came to be driven by the Scot when, in 1960, racing enthusiast Barry Filer was having his race cars prepared by the Stewart family garage and invited a young Jackie Stewart to test with him at Oulton Park.
Following the test Mr Filer bought 'G128' for the 1961 season and signed Sir Jackie to drive for him. As a sign of things to come, the young driver promptly won four sports car races. The Scot moved on in 1962, turning professional and racing Jaguars. The current vendor came into possession of the historic car after purchasing the remains of Marcos Sportscars in the 1990s and has had this famous Xylon tucked away in storage since production ceased at the marque's Wiltshire factory.
Managing director of Silverstone Auctions, Nick Whale, said: "It's fantastic to be offering this car for auction. Jackie Stewart is one of our most legendary racing drivers and therefore it's apt that we are offering it at the home of British motorsport."
The car is offered in 'barn find' condition, needing a total restoration and fresh preparation for any potential racing. He added: "This is a truly great piece of motor racing history which I can't wait to see restored and racing again soon."