The walkway will link East India Dock to the Olympic Park, said London Thames Gateway Development Corporation, which has set aside £15m for the scheme.
Fatwalk, a 3.5 mile-long path-cum-park running alongside the River Lea, is the "backbone" of the main Olympic Park, according to the corporation.
It forms part of the 26-mile corridor that joins London's green belt to the Thames at Blackwall and will boast landscape, paths, cycleways and footbridges.
"You'll be able to walk or cycle along this length of new parkland," said a spokesman of Faltwalk, due for completion in 2012.
"The energetic among us will be able to travel 26 miles from East India Dock Basin, up the Lee Valley, all the way to Ware in Hertfordshire."
London Design Agency, Tower Hamlets and Newham Council have been involved in the project.