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Cillian O'Sullivan

From Cork City, Cillian made his TV debut on TG4 as Danny Flynn in The Running Mate. Before 6Degrees, he had various roles in theatre, short films and television such as Salome, Someone Who'll Watch over Me, Boat Memory (Laurence Olivier Theatre London), Uncle Billls Barrel, An Cosc, Singlehanded and BBC NI/TG4's Seacht.

Most recently playing Christian Ramsay in Ridley Scott's Halo: Nightfall Cillian is currently in rehearsals for Leesa Harker's comedy play Slimmer for Christmas.

Known For

Credits

Cast Credits

Then You Run (2023)
Starring as Orin O'Rourke (7 episodes)
In From the Cold (2022)
Starring as Special Unit Agent Chauncey Lew (8 episodes)
FBI: Most Wanted (2020)
Guest starring as Scot Weitzen
Taken Down (2018)
Guest starring as Dunnie (5 episodes)
Bull (2016)
Guest starring as Nathan Alexander
Chicago P.D. (2014)
Guest starring as Shane Sullivan
The Blacklist (2013)
Guest starring as Skip Sutherland (2 episodes)
Vikings (2013)
Guest starring as Eirik
6Degrees (2012)
Starring as Conor Martin (18 episodes)
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