A 23andMe DNA test taken by Colin Farrell stated that his genetic ancestry is: 98.7% Irish.
Colin Farrell was born on May 31, 1976, in Castleknock, Dublin, Ireland, to Eamon Farrell, a former professional footballer for Shamrock Rovers FC, and his wife Rita. His parents' marital union eventually dissolved. He has an older brother, Eamon Jr., and two sisters, Claudine and Catherine. His older sister Claudine went on to become his personal assistant after he became an actor.
Farrell and his siblings lived with their mother in Castleknock, an area of newer homes just outside Dublin, near one of the world's largest parks.