He was called to the Bar in 1973 and to the Inner Bar in 1985. He had a practice in commercial, constitutional and family law. Two years after commencing practice he appeared as junior counsel for the applicant in State v Donoghue before the Supreme Court, which established a constitutional right to legal aid in criminal cases. Clarke represented Michael McGimpsey and his brother Christopher in a challenge against the constitutionality of the Anglo-Irish Agreement, which was ultimately unsuccessful in the Supreme Court in 1988. He appeared for the plaintiff with Michael McDowell and Gerard Hogan in Cox v Ireland in 1990, where the Supreme Court first introduced proportionality into Irish constitutional law and discovered the right to earn a livelihood. He represented Seán Ardagh and the Oireachtas Subcommittee formed after the death of John Carthy in a constitutional case which limited the powers of investigation of the Oireachtas, which led to the unsuccessful Thirtieth Amendment of the Constitution. Clarke was twice appointed by the Supreme Court for the purpose of Article 26 references. He argued on behalf of the Law Society of Ireland in a referral regarding the Adoption Bill 1987. He was appointed by the Supreme Court to appear to argue on behalf of the rights of the mother in In re Article 26 and the Regulation of Information Bill 1995. He was external counsel to the Laffoy inquiry on child abuse, the Ryan Inquiry, and represented the Flood Tribunal in its case against Liam Lawlor. He was a legal advisor to an inquiry into Deposit interest retention tax conducted by the Public Accounts Committee, along with future judicial colleagues Paul Gilligan and Mary Irvine. He was Chairman of the Bar Council of Ireland from 1993 to 1995. Between 1999 and 2004, he acted as chair of Council of King's Inns. He was a Professor at the Kings's Inns between 1978 and 1985 and was appointed an Adjunct Professor at University College Cork in 2014. He has also been an Adjunct Professor at Trinity College Dublin. Clarke acted as a chair of the Employment Appeals Tribunal while still in practice.
Judicial career
He was appointed a Judge of the High Court in 2004. He was chairman of the Referendum Commission for the second Lisbon Treaty referendum in 2009. As a High Court judge he gave a ruling, on the Leas Cross nursing home case against RTÉ, that the public interest justified the broadcasting of material that otherwise would have been protected by the right to privacy. He frequently presided over the Commercial Court during his time at the High Court. He was involved in the establishment of two High Court lists in Cork, Chancery and a Non-Jury List. Clarke was appointed to the Supreme Court on the 9 February 2012.
Chief Justice of Ireland
On 26 July 2017, it was announced that the Government of Ireland had agreed to nominate Judge Clarke for appointment by the President of Ireland as the next Chief Justice of Ireland, to succeed Susan Denham on the expiry of her term of office. He was the sole name put forward to cabinet for consideration. He applied for the position which included a 500 word application. Upon his appointment, he said it was not "unreasonable" to suggest that he was "socially progressive", while acknowledging his oath of judicial independence. Clarke identified his priorities upon appointment to be to increase access to justice and the legal profession, to improve support and training for judges, and to expand the use of technology in the courts. He oversaw the first live broadcast of the Supreme Court on television in October 2017. The Supreme Court held sittings in Limerick and NUI Galway in 2018 and 2019, the second and third times hearings took place outside of Dublin. He will retire after four years of his term, in 2021. Ruadhán Mac Cormaic of The Irish Times said on his appointment as Chief Justice, that Clarke has a "reputation for fair-mindedness and authority, and for judgments that were incisive and clear". He also noted that he tended not to share an "absolute pro-defendant" attitude to criminal law matters with some Supreme Court colleagues, while also having the perception of more liberal positions than other judges on surrogacy and social issues. Clarke serves on a judicial advisory committee for appointments of judges and advocates general to the Court of Justice of the European Union. In his role as Chief Justice, he was involved in the second inauguration ceremony of President Michael D. Higgins on 11 November 2018 at Dublin Castle. He read out the Declaration of Office for Higgins to sign and then presented the president with his seal of office.
Personal life
He has been married to Dr. Jacqueline Hayden since 1977. They have a son who is a barrister and a daughter who is a carer. He is interested in horse racing and rugby.
