The Miss Universe Organization says the brother-and-sister, song-and-dance stars will perform on the NBC Universal show April 11 from the Planet Hollywood Resort & Casino on the Las Vegas Strip. The network owns the pageant with real estate mogul Donald Trump.
The rival Miss America pageant crowned its 2008 queen in the same casino in January.
Pageant executives say the telecast will represent the first time Donny and Marie Osmond have hosted a prime-time show together since 2000.
Marie Osmond recently competed in ABC's "Dancing With the Stars." Donny Osmond is appearing in "College Road Trip," a Disney comedy starring Martin Lawrence and Raven Symone.
The current Miss USA, Rachel Smith of Tennessee, was crowned last year in Los Angeles.
