Fidelma Macken, SC, (née O'Kelly), is an Irish retired judge who served as a Judge of the Supreme Court from 2005 to 2012, a Judge of the High Court from 1998 to 1999 and between 2004 and 2005 and a Judge of the European Court of Justice from 1999 to 2004.
Fidelma is the central character in the Sister Fidelma series by English author Peter Berresford Ellis. She is a princess-turned-lawyer who solves crime in the abbeys of 7th-century Ireland.