Savol, who appeared on Season 4, spoke as a motivational speaker at a school assembly. He also threw in a few songs.
Principal Hans Lassiter and teachers kept Savol's appearance a secret, so it came as a surprise to students.
Savol will perform in an inspirational play, "The Lord Will Make a Way," at the Memorial Auditorium in in the Progress Center for the Performing Arts in downtown Raleigh Saturday.
On "Idol," Savol earned a reputation as a regular guy in the looks-dominated entertainment industry and was nicknamed "Scotty the Body" by host Ryan Seacrest.