Justin Guarini is an American singer, musician, and actor who first rose to fame as the runner-up on the inaugural season of American Idol in 2002. Following his television debut, he released a self-titled album and starred in the film From Justin to Kelly alongside Kelly Clarkson. Over the years, he has expanded his career to include Broadway, appearing in productions such as Wicked, American Idiot, and In Transit. Guarini has also become known for his role as 'Lil' Sweet' in television commercials for Diet Dr Pepper.