The former sweethearts are both up for the Fiercest Fans prize at the annual ceremony, which celebrates the most popular recording artists among kids and teenagers and takes place at the Nokia Theatre in Los Angeles next month (Apr13).
The couple split earlier this year (13) and will face off at the ceremony to prove who has the most dedicated fanbase.
British boy bands One Direction and The Wanted will battle it out with Mindless Behaviour and R5 for the Best Music Group award while Song Of The Year will be a race between Taylor Swift (I Knew You Were Trouble), Justin Bieber (Beauty And A Beat feat. Nicki Minaj), Cher Lloyd (Want U Back) and One Direction (Live While We're Young).
Bieber is also up against Bruno Mars, Cody Simpson and Austin Mahone for Best Male Artist while Gomez faces competition from Lloyd, Swift and Bridgit Mendler for Best Female Artist.
The ceremony will feature performances from several nominees including Gomez, Swift, Mendler and Lloyd.
Online voting for the nominees closes on 14 April (13).