Aisling O'Sullivan is an award-winning Irish actress who starred in the movie The Butcher Boy as Francie's mentally unstable mother. O'Sullivan previously appeared briefly in another Neil Jordan film, Michael Collins. She had a part as the grieving mother who commits suicide in Six Shooter, playwright Martin McDonagh's Oscar-winning short film.
She is familiar to Irish television audiences as Dr. Cathy Costello from Series 1 to Series 5 in the hugely popular drama series The Clinic, a role for which she has won an IFTA best actress award IN 2008.
She garnered major acclaim for her performance as Widow Quin in Druid Theatre Company's 2004 production of The Playboy of the Western World, which toured throughout Ireland including her native Kerry, and also starred Cillian Murphy and Anne-Marie Duff. In 2011 and 2012, she toured Ireland again with Druid, playing the titular character in Big Maggie by John B. Keane and was consequently nominated for Best Actress in the Irish Times Irish Theatre Awards. She also had a leading role in the Channel 4 thriller Shockers.