Lambert will host and perform at the Dec. 16 event. Miley Cyrus, Demi Lovato, Kelly Rowland, Jordin Sparks and Ciara will also hit the stage at the special honoring dance music and its current and classic divas.
Tributes to Whitney Houston and Donna Summer are also planned.
Lambert said in a statement Thursday the show will be "the most fabulous concert of the year."
"VH1 Divas" will benefit VH1's Save the Music Foundation. The venue for the event hasn't been announced. The show will air live at 9 p.m. Eastern.