Robert made his acting debut in Aisling Walsh’s acclaimed feature film Song For A Raggy Boy. Since then, features include Ghostwood (Maxim Pictures), Summer of the Flying Saucer (Magma), Season of the Witch (Atlas Entertainment), Cherrybomb (Generator Entertainment), Killing Bono (Generator/Cinema Three), The Mortal Instruments: City of Bones (Constantin Films), The Road Within (Amasia Entertainment), Anita B (Jean Vigo Italia), The Messenger (Gateway Films), Moonwalkers (Partizan), Jet Trash (Aimimage), Geostorm (Warner Bros/Netflix), Bad Samaritan (Electric Entertainment), Three Summers (TSF Productions), Mute (Liberty Films), Mortal Engines (MRC/Universal).
Television includes Foreign Exchange (Magma Film/9 Network Australia), Young Blades (Insight/PAX TV), all three films in the BAFTA award winning Red Riding trilogy (Revolution Films/Channel 4), multi IFTA award winning Love/Hate, for which he was twice nominated for Best Actor (RTE/Octagon Films), BAFTA award winning Misfits (Clerkenwell/E4), which he was also BAFTA nominated for Best Supporting Actor, The Borrowers (Working Title/BBC), Me and Mrs Jones (BBC/Hartswood Films), The Accused (BBC), Fortitude (Fifty Fathoms/Sky Atlantic), Genius: Picasso (National Geographic), The Umbrella Academy (Universal/Netflix).
On stage he has appeared at the Old Vic Theatre in the title role in The Playboy of the Western World, directed by John Crowley, and as Richard III in The Wars of the Roses, directed by Trevor Nunn.