Sean Casey along with his brother, Michael Casey, were members of the True IRA in Belfast on the FX original series Sons of Anarchy. Played by American actor Dan Hildebrand, Sean makes his debut on the episode "Oiled" in the series' third season. He and his brother are so close to Father Kellan Ashby that Fiona Larkin describes them as "being like sons to him", and, playing a recurring role through the same season, he meets his demise in the Season 3 episode "Bainne".
Following Father Ashby's order, they killed Cameron Hayes, and disposed of his body. Sean is shown to be adept in the art of torture when he uses various tools to extract information from Liam O'Neill. After Father Ashby reneges on his deal and tells Jax that Abel has been adopted, Jax stabs and threatens to kill Sean to make Kellan tell him where Abel is. Sean is kidnapped and tortured by Jimmy O'Phelan for information about Abel Teller and then executed.
|Season 3 appearances|
|"SO"||"Oiled"||"Caregiver"||"Home"||"Turning and Turning"|
|"The Push"||"Widening Gyre"||"Lochán Mór"||"Turas"||"Fírinne"|