"The six-hour race...on November 19 will be the last time the reigning World Champion from Australia will compete as a works driver," the manufacturer said in a statement.
Webber, 40, will become a Porsche 'special representative' at global events and work as a consultant on motorsport programmes.
The Australian won the World Endurance title with Porsche in 2015 with Germany's Timo Bernhard and New Zealander Brendon Hartley.
"I will miss the sheer speed, downforce and competition, but I want to leave on a high and I’m very much looking forward to my new tasks," said the winner of nine Formula One grands prix with Red Bull.
He competed in 215 Formula One races for Minardi, Jaguar, Williams and Red Bull before leaving in 2013.
"It was a big change from Formula One to LMP1 (Le Mans Prototype) and an entirely new experience. But it came at the right time for me," said Webber.
"It will be strange getting into the race car for the very last time in Bahrain but for now I will thoroughly enjoy every moment of the remaining races."
(Reporting by Alan Baldwin, editing by Pritha Sarkar)
