Iseult Mary O'Malley (born 6 June 1964) is an Irish judge who has served as a Judge of the Supreme Court of Ireland since October 2015.
She previously served as a Judge of the High Court from 2012 to 2015.
She was educated at Trinity College, Dublin and King's Inns.
She is a granddaughter of Kevin O'Higgins, the Minister for Justice who was assassinated in 1927.
She was called to the Bar in 1987, and became a Senior Counsel in 2007.
She was appointed as a Judge of the High Court in 2012.
She had practised mainly in criminal law, and was Director and Chair of the Free Legal Advice Centres (FLAC) from 1985 to 2012.
She won a Person of the Year Award in 2004 for her work with FLAC.
She was appointed a Bencher of the King's Inns in 2012.She was nominated to the Supreme Court in July 2015 and was appointed by the President of Ireland on 1 October 2015.
She made the Declaration required by the Constitution of a Justice of the Supreme Court on 6 October 2015.