
Brían Francis O'Byrne (born 16 May 1967) is an Irish actor who works mostly in the United States. He was born in Mullagh, County Cavan. O'Byrne first attracted notice for his performances in the Martin McDonagh plays The Beauty Queen of Leenane (1996) as Pato Dooley (for which he received a Tony Award nomination for Best Featured Actor in a Play) and The Lonesome West (1997). He is known for taking on serious and dramatic roles, such as a serial killer in Frozen (1998) (for which he won a Tony Award) and a priest accused of child molestation in Doubt (2004), for which he received a Tony nomination. O'Byrne also appeared as a priest in the 2004 film Million Dollar Baby. In May 2007, O'Byrne was nominated for a Tony Award for his performance as Alexander Herzen in Tom Stoppard's 2002 trilogy The Coast of Utopia. In 2011, he was nominated for the Primetime Emmy Award for Outstanding Supporting Actor in a Miniseries or a Movie for his performance in Mildred Pierce as Bert Pierce.
Prisoner
2026
The Abandons
2025
Dead of Winter
2025
Conclave
2024
Twig
2024
The Wonder
2022
My Salinger Year
2020
Sergio
2020
Hatton Garden
2019
Nightflyers
2018
Manhunt
2017
Little Boy Blue
2017
The Magicians
2015
Aquarius
2015
Queen & Country
2015
The Last Ship
2014
Jimmy's Hall
2014
Medeas
2013
Gilded Lilys
2013
Prime Suspect
2011
Mildred Pierce
2011
Love/Hate
2010
FlashForward
2009
No Reservations
2007
Bug
2007
Brotherhood
2006
The New World
2005
Easy
2003
Intermission
2003
Mapmaker
2001
Bandits
2001
Disco Pigs
2001
The Grey Zone
2001
Amongst Women
1998
Oz
1997
Avenue X
1993



















































