Els injured his knee after the British Open and has been sidelined since due to arthroscopic surgery on the knee.
Nedbank Challenge tournament director Alistair Roper announced Els' return on Thursday.
'We could have announced six weeks ago that Ernie would be playing, but we decided to give him time to evaluate his fitness and make 100 percent sure he would play,' Roper said. 'We agreed that he would undergo an evaluation by his doctors on September 30, and then we would sign the contracts. I spoke to Ernie yesterday and he was playing golf.'
Els, the world No. 5 and three-time champion of the Nedbank Challenge, had targeted the South African Open, which starts on December 15th, as his return date. By playing in Sun City, Els beat that target date by two weeks.
The South African will be joined in the 12-player field by 2004 champion and fellow South African Retief Goosen, 2001 and 2003 winner Sergio Garcia, Jim Furyk, Adam Scott, Chris DiMarco, Stewart Cink, South African Tim Clark, Darren Clarke, Luke Donald, Angel Cabrera and Kenny Perry.