CMT confirmed Tuesday that Ballerini, 27, and Halsey, 26, will take the stage during the awards show next week.
Luke Combs and Brooks & Dunn, Jimmie Allen and Noah Cyrus, Shania Twain, Sam Hunt, Gabby Barrett, and Morgan Wallen have also joined the list of performers. Previously announced performers include Dan + Shay, Little Big Town, Luke Brown, Maren Morris and Hardy.
Country music singer Kane Brown and Modern Family actress Sarah Hyland will host the awards show, which airs Oct. 21 at 8 p.m. EDT on CMT, MTV, MTV2, Logo, Paramount Network, Pop and TV Land. Two additional co-hosts have yet to be announced.
Ballerini and Halsey are nominated for Performance of the Year for their performance of "Graveyard" on CMT Crossroads. Ballerini is also nominated for Video of the Year and Female Video of the Year for "homecoming queen?"
Other nominations include Barrett for Female Video of the Year and Breakthrough Video of the Year for "I Hope," and Wallen for Male Video of the Year for "Chasin' You (Dream Video)."
The awards show will mark Twain's first CMT Music Awards performance since 2011. In addition, the show will be Wallen's first performance since Saturday Night Live canceled his performance due to his breaking of COVID-19 protocols.