A native of Dundalk, County Louth Mr MacGuill graduated with a degree in law from College Cork in 1983 and was admitted to the roll of solicitors in 1986. He subsequently gained a Diploma in Arbitration in 1991 and was appointed a Notary Public in 1996.  

In 2020 he was one of the first solicitors in Ireland to be appointed as senior counsel.

His practice included domestic and international cases, both within and outside the European Union. He successfully represented a client before the Court of Justice of the European Union last year in a case that forced the reform of Ireland’s criminal injuries compensation scheme to include compensation for pain and suffering.

Mr MacGuill was also actively involved in The Law Society of Ireland and chaired many of its committees including criminal law, human rights, professional indemnity insurance and finance. He served as President of the Law Society from 2007 to 2008.  

He was chair of the criminal law committee of the Council of Bars and Law Societies of Europe from 2013 to 2022.

Senior counsel Giollaíosa Ó Lideadha told the Irish Times thar Mr MacGuill was “a brave and brilliant advocate for human rights and for restraining the abuse of power” who “used his energy, expertise, intelligence and wit to make a positive difference in people’s lives”.

Mr MacGuill is survived by his son Conor Kirby MacGuill, his brothers Ciarán, Daire and Conor and his sister Eithne.