In 2005, as a member of the Essentials, Fontana co-wrote the musical comedy Perfect Harmony, and originated the role of Philip Fellowes V. In 2006, he starred as Matt in the Off-Broadway revival of The Fantasticks. His Broadway debut was Sunday in the Park with George in 2007. Fontana originated the role of Tony in the Broadway production of Billy Elliot from October 1, 2008 to July 4, 2009. He was awarded the 2010 Drama Desk Award for Best Featured Actor in a Play for his work in Brighton Beach Memoirs. He starred as Prince Topher in Rodgers & Hammerstein's Cinderella on Broadway, for which he was nominated for a Tony Award for Best Leading Actor in a Musical.