Justin Guarini is an American singer, songwriter and actor who in 2002 was the runner-up on the first season of American Idol.

The first season of American Idol premiered on June 11, 2002, over four months after Pop Idol's first series ended [with Will Young winning the series], and continued until September 4, 2002. The first season was co-hosted by Ryan Seacrest and Brian Dunkleman, the latter of whom left the show after the season ended. Paula Abdul, Simon Cowell, and Randy Jackson served as judges. Kelly Clarkson won the competition, defeating Justin Guarini, who finished in second place.