Winner of the 2010 Open Championship, Oosthuizen's missed eagle-putt on the final hole last year deprived him of a play-off spot for the $1m jackpot at the co-sanctioned tournament.
The world number 12 confirmed his entry together with Ireland's Padraig Harrington (three Majors) and New Zealand's Michael Campbell (one Major) for the November 8-11 tournament.
The trio join a field spearheaded by world number one Rory McIlroy of Northern Ireland, three-times winner Adam Scott of Australia and American Phil Mickelson.
For the past two seasons, Sentosa's Serapong and Tanjong Courses have been utilised for the tournament but this year only the former will be used.
Oosthuizen has enjoyed a solid season with victories in January's Africa Open, the Malaysian Open and a play-off loss to Bubba Watson at the US Masters, and he is hoping for more success as the Race to Dubai reaches a climax.
"I'm very happy with the season but it can always improve," said Oosthuizen, who lies sixth on the Race to Dubai, just over one million euros behind McIlroy.
"I'm still fighting. I want to get up in the world ranking - get to maybe sixth or seventh - and I've still got the Race to Dubai (in my sights).
"I know I'm quite a bit behind Rory still, but if I play well I've got a good shot. I need to get myself within probably 300,000 to 400,000 euros (before the final event) to have a real chance."
- Sports & Recreation
- Rory McIlroy
- Padraig Harrington