He's not former President Bill Clinton, but Ben Affleck (search) will do.
Clinton had been invited to host the not-ready-for-prime-time show but turned down the offer, NBC said last month. No reason was given for Clinton rejecting the offer.
The former president has since undergone open-heart surgery.
Affleck, 32, recently made headlines when he boisterously appeared throughout the Democratic National Convention in Boston, his hometown. His films include "Jersey Girl" and "Paycheck." The actor's latest movie, the holiday comedy "Surviving Christmas" with James Gandolfini (search) and Christina Applegate (search), is due in theaters Oct. 21.
Rapper Nelly will perform songs from his new CDs, "Sweat" and "Suit."
The hosting gig marks Affleck's third appearance on the live sketch-comedy show. It's Nelly's second.