Rea was married for 17 years to Dolours Price, a former Provisional Irish Republican Army bomber and hunger striker who later became a critic of Sinn Féin. (Another news source suggests a marriage of 20 years, from 1983 to 2003.) Price attended a performance of Rea’s at the Court Theatre in London in 1973, the night before she participated in a car bombing which injured 200 people. They had been divorced when she died on 23 January 2013. They have two sons.

Rea’s friendship with American playwright and actor Sam Shepard dates back to the early 1970s, and he starred in Shepard’s directorial début of his play Geography of a Horse Dreamer at the Royal Court Theatre in 1974. In 2007, Rea began a successful and acclaimed relationship with both the Abbey Theatre and Sam Shepard, appearing in Kicking a Dead Horse (2007) and Ages of the Moon (2009), both penned by Shepard and also both transferred to New York. Rea returned to the Abbey in 2009 to appear in the world première of Sebastian Barry’s Tales of Ballycumber.

Rea helped establish the Field Day Theatre Company in 1980 with Tom Paulin, Brian Friel, Seamus Heaney and Seamus Deane. In recognition for his contribution to theatre and performing arts, Rea was given honorary degrees from both the Queen’s University Belfast and the Ulster University in 2004.

In 2011, Rea featured in the BBC crime drama The Shadow Line, playing antagonist Gatehouse.

In April 2012, Rea read James Joyce’s short story “The Dead” on RTÉ Radio 1. He also narrated for the BBC Radio 4 production of Ulysses for Bloomsday, 16 June 2012.