The veteran Australian driver, who has won nine races in a 203 start career, is joining Porsche’s new sportscar programme.
Webber had opportunities to stay in F1, with Red Bull, or another team, but decided it was time to move on.
“Porsche has written racing history as a manufacturer and stands for outstanding performance and technology at the highest level,” said the New South Walian.
“I’m very much looking forward to this new challenge after my time in Formula 1. I can hardly wait to pilot one of the fastest sports cars in the world.”
Webber has struggled with his position as Red Bull’s number two driver leading to a poor relationship with his teammate Sebastian Vettel.