Following his education at NIDA, Samuel began writing and directing a number of short films including Sanctuary which was released in 2012 and will star his brother Xavier Samuel in the leading role. In theatre, he performed in Sex Wars, a production he appeared in during his time at NIDA. He played a part in 'Tis Pity She's a Whore at the Malthouse Theatre in Melbourne. In 2011, Benedict has appeared on several Australian television series, the mini-series Paper Giants: The Birth of Cleo and the children's series My Place. He is known for playing the role of Harman "Hammer" Pirovic on Seven Network soap opera Home and Away, for which he appeared for several episodes until his character was killed off in a showdown between Hammer, Charlie Buckton and Darryl Braxton. Benedict also appeared in the short film Kiss. He appeared as Owen, a member of the Wolves gang, in the American post-apocalyptic zombie series The Walking Dead and as Jacob Harding in the thriller film The Stanford Prison Experiment. In 2016, Samuel was cast as famous Batman villain The Mad Hatter, the main antagonist of the third season of Gotham. He continued to play the character in a recurring capacity during the fourth season.