In 2010, at the age of 14, Casillo participated in the television program Io Canto hosted by Gerry Scotti. During the program he became part of the boy band group Gimme Five.
On 31 May 2011 he released his first EP titled Raccontami chi sei, which was produced by GPM, RTI Music. The EP contains five songs written his brothers Matteo, Emiliano and Maurizio Bassi. One of the songs of the EP was premiered on May 28 at the Wind Music Awards.
He was a SanremoSocial winner of the Sanremo Music Festival 2012, having sung È vero (che ci sei) (English: It is true (you're there)). He was unable to attend the award ceremony, because according to a legislative degree (n. 345), minors cannot work in television after midnight. He received the prize then the next day, during the final show.
On February 15, 2012 his debut album È vero was released. It contains nine original songs and a cover of Baltimora'sTarzan Boy.
On May 5, 2012 Casillo participated in the TRL Awards 2012. During the summer of 2012 he was the opening act for Noemi's RossoNoemi concert tour.
In January 2014 Casillo released his new Album "#ALE".