Stone is a celebrity chef and competitor on "The Celebrity Apprentice." Morales is a "Today" show co-host and correspondent.
The Miss USA Pageant is to take place May 16 at the Planet Hollywood Resort & Casino. It is to air on NBC.
The program will also feature country star Trace Adkins and pop-rock act Boys Like Girls debuting their latest singles.
Mother-daughter duo Joan and Melissa Rivers are to provide backstage color commentary of the contest, as well.
Details regarding the pageant were unveiled Wednesday by NBC, Donald J. Trump and Paula M. Shugart, president of the Miss Universe Organization.
"We have 51 of the most beautiful women in the country competing in one of the best live shows on television," producer Trump said in a statement. "I know Curtis and Natalie will do a great job hosting and with Joan and Melissa backstage, anything can happen. It's going to be a fantastic show."