Theatre work includes: The Lonesome West (Gaiety Theatre), Krapp’s Last Tape (Blood in the Alley Productions), Alone in Berlin (Royal Derngate Theatre), The Lieutenant of Inishmore (West End), The Gigli Concert (The Gate Theatre), Glengarry Glen Ross (ATG Tour).
Film work includes: Aisha (BBC Films), Brooklyn (Parallel Films), Garage (Element Pictures), The Wind That Shakes The Barley ( Element Pictures), Alexander (Warner Brothers).
Television work includes: Bodkin (Higher Ground Productions), Blood (Virgin Media One) Penny Dreadful (Showtime) Single-Handed (RTÉ)
Denis has twice won the Irish Times Best Actor Award, for his roles in The Gigli Concert and Richard III. He received an IFTA Best Actor Nomination for The Running Mate.