Pro Mark Ballas will choreograph the number.
Fatone and Rycroft were picked by fans to perform in a contest called Design a Dance. Viewers also chose the dance style, song and costume design.
The two will dance to "Rock and Roll All Nite" by Kiss.
Rycroft is a former Dallas Cowboys cheerleader who appeared as a contestant on "The Bachelor." Fatone was a member of boy band 'N Sync.
The season finale of "Dancing with the Stars" will air May 25.