Underwood received her nod in the Favorite Female Country Artist category, where she'll compete against Reba McEntire and Taylor Swift.
Underwood is no stranger to winning at the AMAs -- as she claimed Favorite New Breakthrough Artist honors in 2006 and won Favorite Country Artist and Artist of the Year awards in 2007.
In addition, her debut album "Some Hearts" won Favorite Country Album in 2007, while her second album "Carnival Ride" claimed the award last year.
Daughtry's band Daughtry was nominated in the Favorite Adult Contemporary Artist category, where it will compete against Swift and Jason Mraz.
Daughtry has also done fairly well in winning AMA honors in previous years. The group went 3 for 3 in 2007 when it claimed Breakthrough Artist and Best Contemporary Artist honors, as well as Best Pop/Rock Album for its self-titled debut.
Last year the band took home Favorite Band Duo or Group, Pop or Rock Music.
Day26 -- which was formed by Sean "Diddy" Combs on Making the Band 4 in 2007 -- received its first AMA nod in the Favorite Soul/R&B Band Duo or Group category, where it will compete against Black Eyed Peas and Mary Mary.
For the third year in a row, the AMA's 2009 winners will be determined by online voting conducted via ABC's website.
The 37th Annual American Music Awards ceremony will air live on Sunday, November 22 at 8PM ET/PT on ABC and include a performance by Idol eighth-season runner-up Adam Lambert, whose debut album will drop on November 24.