Susan Jane Denham, SC (née Gageby), Irish judge who is the first woman to hold the position of Chief Justice of Ireland (2011-17), is born in Dublin on August 22, 1945. She serves as a Judge of the Supreme Court of Ireland (1992-2017), and is the longest-serving member of the court on her retirement. She also serves as a Judge of the High Court (1991-92).

Gageby is the daughter of the former editor of The Irish Times, Douglas Gageby, the sister of another barrister, Patrick Gageby, and maternal granddaughter of Seán Lester. She is from a Church of Ireland background. She is educated at Alexandra College, Dublin, and attends Trinity College Dublin, the King’s Inns, and the Law School of Columbia University, New York City (LL.M. 1972). She is involved with the Free Legal Advice Centres while studying in Dublin and is a founder and president of the Archaeology and Folklife Society at Trinity College.

Gageby is called to the bar in July 1971 and becomes a Senior Counsel in October 1987. She is the fourth woman to enter the Inner Bar. She becomes a senior counsel on the same day as future Supreme Court colleague Mary Laffoy. She works on the Midland circuit until 1979, following which she is based in Dublin. She is involved in a number of leading cases while a junior barrister and a Senior Counsel particularly in the area of judicial review. She becomes a High Court judge in 1991.

Gageby marries paediatrician Dr. Brian Denham in 1992. Also in 1992, at the age of 47, Denham is the first woman appointed to the Supreme Court. She is considered for appointment to the role of President of the High Court in 1994, but declines to have her name put forward. She makes two dissents early on in her period on the Court. Throughout her tenure as a judge she is seen by commentators to be a “liberal” judge.

In Kelly v Hennessy in 1996, Denham outlines criteria for a court to consider the evidence of the existence of nervous shock in Ireland. In 2001, she is the sole member of the Supreme Court to dissent in TD v Minister for Education. The court overturns a decision of Peter Kelly in the High Court to direct the government to build secure care units for certain children.

From 1995 to 1998, Denham chairs the Working Group on a Courts Commission, which is responsible for a significant reform of the organisation of the courts since the foundation of the state. It leads to the establishment of the Courts Service. She is on the Interim Board of the Court Service and serves on the Board of the Court Service from its inception, and chairs the board from 2001 to 2004. She chairs the Committee on Court Practice and Procedure which recommends in 2002 the establishment of a commercial court within the High Court.

From 2006, Denham chairs the Working Group on a Court of Appeal. The report of the group is published by the government in August 2009 and recommends the establishment of a general Court of Appeal. This is ultimately established in 2014, after a referendum in 2013.

Denham is part of the Irish delegation which, with the Netherlands and Belgium, establishes the European Network of Councils for the Judiciary (ENCJ) and she continues an involvement in this Network. From January 1, 2015 to December 31, 2016, she is President of the Network of the Presidents of the Supreme Judicial Courts of the European Union which is an association of Supreme Court Presidents and Chief Justices of EU Member States.

Denham writes the judgment in McD v. L (2009), upholding the parental rights of a sperm donor.

On July 4, 2011, Denham is nominated by Taoiseach Enda Kenny to become Chief Justice of Ireland, and is appointed as Chief Justice by President Mary McAleese on July 25, 2011. She is the first woman appointed to the office and as a member of the Church of Ireland, she is the first non-Catholic to hold the position. She is also the first graduate of Trinity College Dublin to have been appointed as Chief Justices have largely been graduates of University College Dublin. She succeeds John L. Murray.

During Denham’s tenure as Chief Justice, the Supreme Court issues suspended declarations of unconstitutionality for the first time. The possibility to delay the effect of a court declaration that a piece of legislation is contrary to the Constitution is first explored by Denham in A v Governor of Arbour Hill Prison. The court first adopts this approach in N.V.H. v Minister for Justice & Equality in May 2017.

As Chief Justice, Denham oversees changes in the operations of the Supreme Court and the courts generally. She oversees the removal of the requirement for judges to wear wigs while hearing cases. In 2015, the Supreme Court sits outside Dublin for the first time since 1931, sitting in Cork. She corresponds with the Office of Public Works over the lack of heating in the Four Courts, threatening to cancel sittings if the issue is not resolved. She advocates for the inclusion of a new courtroom for the Supreme Court in plans to develop a new family court complex on Hammond Lane.

In her capacity as Chief Justice, Denham oversees the administration of the Presidential Declaration of Office at the inauguration of President Michael D. Higgins in Dublin Castle in November 2011.

Denham retires from the position in July 2017, and is succeeded by Judge Frank Clarke. She is the third-longest serving Supreme Court judge ever at the time of her retirement. In her remarks on her retirement, she draws attention to the government’s failure to institute a judicial council, having first attempted to persuade the government to establish one in 1997.

In 2019, Denham is made an honorary fellow of Trinity College Dublin, where she was a Pro-Chancellor from 1996-2010.

The Courts Service announces on August 24, 2020 that the Supreme Court has appointed Denham to review the attendance of Supreme Court judge Séamus Woulfe at a dinner organised by the Oireachtas Golf Society. She is appointed on a non-statutory basis as the relevant section in the Judicial Council Act 2019 on judicial conduct has not yet been commenced.