The team will put on the event, down the length of the Midsummer Boulevard in the town where their factory is based, to mark their back-to-back successes in the Formula One driver's and constructors' championships.
Vettel, the world champion, and team-mate Webber will each drive a car along the route.
Red Bull team principal Christian Horner said: ""It's great news to be able to go ahead with this event in Milton Keynes with both drivers and two cars. It's been home for our factory since Red Bull entered Formula One in 2005 and we get excellent support; it will be fantastic to be able to put on a show and give something back.
"I think most of the staff will be attending with their families, which I'm extremely pleased about. I'd like to thank the council for all their efforts and I'm looking forward to the event - it will be the first time we'll have two cars and both of our drivers at a running show car event, so it will be a great way to finish the year."