Jesse McCartney

He's nowhere near as famous as Ariana Grande, Justin Timberlake or other singers who started out as child actors, but Jesse McCartney very pretty popular in the teenage girl demographic in the mid-'00s, when he was on the WB series Summerland and had a hit song with "Beautiful Soul." His acting career started even earlier: He was on the soap opera All My Children from 1999-2011, starting when he was 11 years old.

He was in a boy band called Dream Street while he was also on All My Children. During this time he was attending Ardsley High School, a public school in Westchester County, New York. Most of his classmates didn't know about his famous extracurriculars until one day when the principal congratulated him on his Daytime Emmy nomination for Outstanding Younger Actor in a Drama Series during announcements.

His boy band Dream Street had some success on Nickelodeon, which played their video for "It Happens Everytime" in 2001.