Ballerini was selected new female artist of the year, with Stapleton named new male artist and Old Dominion new duo/group.
Previously fan-voted, the newcomer categories are now all incorporated into the professional membership voting process this year.
These awards mark the first-ever ACM Award wins for Ballerini, Stapleton and Old Dominion.
Stapleton leads the ACM nominations with six additional nods, including album of the year (for Traveller) and male vocalist of the year. Ballerini is also nominated for female vocalist of the year, and Old Dominion is up for vocal group of the year.