Colm J. Meaney (; Irish: Colm Ó Maonaigh; born 30 May 1953) is an Irish actor best known for playing Miles O'Brien in Star Trek: The Next Generation (1987–1994) and Star Trek: Deep Space Nine (1993–1999). He has guest-starred on many TV shows including Law & Order and The Simpsons, and starred as Thomas C. Durant on Hell on Wheels (2011–2016).
He has a career in films, appearing in Layer Cake, The Damned United, all three film adaptations of Roddy Doyle's The Barrytown Trilogy, and in Get Him to the Greek. He portrayed a principal character in the film The Englishman who Went up a Hill but Came down a Mountain. In 2017, Meaney won the Best Actor IFTA for his portrayal of Irish politician Martin McGuinness in the film The Journey. In 2020, he was listed at number 24 on The Irish Times list of Ireland's greatest film actors.
Source : Wikipedia