Catherine McGuinness (; born 14 November 1934) is a retired Irish judge who served as a Judge of the Supreme Court from 2000 to 2006, a Judge of the High Court from 1996 to 2000, a Judge of the Circuit Court from 1994 to 1996 and a Senator for the Dublin University from 1979 to 1981 and between 1983 and 1987. She was appointed by President Patrick Hillery to the Council of State from 1988 to 1990 and by President Michael D. Higgins from 2012 to 2019. She was President of the Law Reform Commission from 2007 to 2009. In May 2013, she was appointed Chair of the National University of Ireland Galway Governing Authority. Biography Catherine Isobel Bridget Ellis was born in Belfast, Northern Ireland, in 1934 to Canon Robert Ellis and his wife, Sylvia Craig. She attended primary school in Belfast, and was later educated in Alexandra College, Trinity College Dublin and the King's Inns. In the 1960s, she worked for the Labour Party. She was called to the Irish Bar in 1977 at age 42. In 1989, she was called to the Inner Bar. In 1979, she was elected as an independent candidate to Seanad Éireann at a by-election on 11 December 1979 as a senator for the Dublin University constituency, following the resignation of Conor Cruise O'Brien, taking her seat in the 14th Seanad. She was re-elected at the 1981 elections to the 15th Seanad, and in 1983 to the 17th Seanad, where she served until 1987. She lost her seat to David Norris. She was appointed to the Council of State on 2 May 1988 by President Patrick Hillery and served until 1990. She was appointed a judge of the Circuit Court in 1994, the first woman to hold that office in Ireland. In 1996, she was appointed to the High Court and remained there until her appointment to the Supreme Court in January 2000. In November 2005, she was appointed adjunct professor at the Faculty of Law, National University of Ireland, Galway. She was also appointed President of the Law Reform Commission in 2005, and held that position until 2011. In April 2009, she was awarded a "Lord Mayor's Award" by Lord Mayor of Dublin Eibhlin Byrne "for her contribution to the lives of children and families in the city through her pioneering work". In September 2010, she was named as one of the