When Robert was 15, he started acting in amateur plays with the Barnes Theatre Company. Afterward, he took screen role like Ring of the Nibelungs (2004) (TV) (Kingdom of Twilight) as Giselher.
In 2003, Robert took on the role of Cedric Diggory in Harry Potter and the Goblet of Fire (2005). He got his role a week later after meeting Mike Newell in late 2003.
He has since been cast as Edward Cullen in the highly-anticipated film, Twilight (2008/I). His music will also be heard in the film. Additionally, Robert has completed upcoming roles as Salvador Dalí in Little Ashes (2008) and Art in How to Be (2008).