Mills most recently made headlines for her high-profile divorce from British rock 'n' roll icon Paul McCartney.
The panel includes San Diego Chargers linebacker Shawne "Lights Out" Merriman, celebrity hairstylist Ken Paves, actress Kelly Carlson and Vanity Fair celebrity journalist George Wayne, as well.
Donny and Marie Osmond are to preside over the 57th Annual Miss USA Pageant from the Planet Hollywood Resort & Casino April 11.
"Nothing could be better than two iconic hosts, a 'paralyzing' performance and world-class judges in Las Vegas with the hottest women in the country," Paula Shugart, president of the Miss Universe Organization, said in a statement. "A perfect combination that will make this live telecast the sexiest and most exciting in our 57-year history!"