The St. John XXIII Choir is an auditioned group of top vocal students in grades 5-8. Any student in grades 5-8 is eligible to audition for the ensemble. The choir performs two school concerts per year, and every spring they participate in the Kings Island Choral Music Festival, receiving high scores. Many students participate in the Ohio Music Educator's Association District 13 Honor Choir every February.
The choir is often invited to perform at extra events throughout the year. Previous invitations include Middletown Christmas Tree Lighting, St. John XXIII Wine and Cheese, Judicial Oath Ceremony, and singing the national anthem for Bishop Fenwick High School football and basketball games.