"Jamie Foxx is not going to walk out of that place without an Oscar," Rock was quoted as saying by imdb.com.
While the Academy Award nominations are yet to be announced, Rock, who is hosting the ceremony, is confident Foxx will win the best actor award.
"I am rooting for Jamie, and if he doesn't win, I'm going to talk about it on the show.
"I'll take an Oscar from one of the sound or light people that win and give it to him," he said.
Another favourite for the best actor Oscar is Leonardo DiCaprio for his role in Martin Scorsese's biopic "The Aviator".
Both Foxx and DiCaprio won best actor awards at the recent Golden Globe ceremony. Foxx won in the category of best actor in a comedy or musical, while DiCaprio won as best actor in a drama.