McCreery, 17, beat out fellow finalist Lauren Alaina, 16, for the honor.
Alaina blew out a vocal cord during rehearsal this week, but recovered in time to perform on the final night of competition Tuesday. EW.com said more than 122 million votes were cast after the show.
The winner was announced Wednesday.
Iranian woman stops the execution of son's killer
Disney's 'Jessie' to feature network's first engagement