Jason was born and raised in Dublin, Ireland. Graduated from Trinity College Dublin with a BA in Drama. He was an avid rugby player and had no interest in acting until a neck injury sidelined him. During his recovery, tried out for a school production of The Merchant of Venice and won a role. Worked on the stage and for the BBC before making his American TV debut in the miniseries Band of Brothers (2001). Met his wife Paige Turco when they starred together in the CBS drama The Agency.