Bradford was born in Norwalk, Connecticut, the only child of commercial actors; his cousins are Jonathan Svec (a member of the bands Splender and Edison) and Sarah Messer, a well-known writer and poet. He began acting at the age of eight months, appearing in a Q-Tip commercial. At his parents' encouragement, Bradford began modelling and auditioning for acting roles; his first film appearance was as Robert De Niro's son in Falling in Love (1984). Bradford went to Brien McMahon High School, where he was Homecoming King. He went on to attend Columbia University, from which he graduated with a degree in film in 2002.
Bradford starred, as a child actor, in the well-reviewed films King of the Hill (1993) and Far From Home (1995). Subsequently, he has had several notable roles in motion pictures, including Romeo Juliet (1996) and the cult hit Bring It On (2000), playing the romantic interest. In 2002, Bradford appeared as the lead in two major films; Clockstoppers and Swimfan. He has also had a minor role as a White House intern on television's The West Wing, appearing in nine episodes as a guest actor during the show's fifth season.
Bradford is currently filming the movie Flags of Our Fathers, based on the book of the same name by James Bradley. The film is about the battle of Iwo Jima and is being directed by Academy Award-winning director Clint Eastwood.
Bradford enjoys music, playing the guitar and snowboarding. He is ambidextrous.
Bradford was involved a minor automobile accident in Beverly Hills on August 17, 2002. He sustained some injuries and was treated at Cedars Sinai Hospital; no one else was injured.