The Hollywood star is the latest name to be revealed for Jon Favreau’s adaptation of Rudyard Kipling’s book.
Giancarlo Esposito, who starred in the television series Breaking Bad, will also join the cast in the film which is a mixture of live action and computer-generated animation.
Walken is taking on the role of the ape who became famous for singing I Wanna Be Like You in the 1967 animated version.
The character, which was voiced by Louis Prima, did not feature in the original book as orangutans are not native to India where it is set.
The duo join Ben Kingsley as Bagheera, Lupita Nyong’o as Raksha, Idris Elba as Shere Khan, Scarlett Johansson as Kaa and newcomer Neel Sethi as Mowgli – the only actor to physically appear on screen.
The 3D picture has an October 2015 release date.