He played a preteen murderer-rapist in an episode of Law & Order: Special Victims Unit.[5] He made his motion picture debut in Clint Eastwood's Oscar-nominated Mystic River, playing young Sean. In 2004, Paolo was on One Life to Live as Travis O'Connell, a recurring character. Paolo also made a return appearance on Law & Order: Special Victims Unit, playing a disturbed teenager based on the real case of Justin Berry.[6] Other films include World Trade Center for Oliver Stone in 2006; Snow Angels, directed by David Gordon Green; and Favorite Son, his first leading role.
In April 2011, Paolo joined the cast of ABC's dramatic series Revenge. In August 2011, Paolo stated that he would be taking on the new series Revenge full-time and his character Eric van der Woodsen on Gossip Girl would no longer appear on the show.[9] He, however, returned to Gossip Girl for a brief appearance during the series finale.[10] Paolo exited Revenge in May 2013, after his character was written off the second season finale.[11]
In 2020, Variety announced Paolo was joining the cast of the Chris Blake quarantine comedy Distancing Socially. The film was shot at the height of the COVID-19 pandemic in 2020, using remote technologies and the iPhone 11. The film was acquired and released by Cinedigm in October 2021.[12]