He acted in cases before Irish and European courts, was a legal assessor at professional misconduct tribunals and lectured in law.

During his tenure in office, he advised on the referendum to replace the Eighth Amendment, the constitutionality of the Occupied Territories Bill and legislation related to the COVID-19 pandemic.

[9] He held several appointments, including Legal Assessor to the Fitness to Practise Committees of the Irish Medical Council and the Nursing and Midwifery Board of Ireland.

[10] He appeared with Adrian Hardiman and Iseult O'Malley in 1993 for Rabbitte and Tomás MacGiolla in Attorney General v. Hamilton which clarified the law on parliamentary privilege in Ireland.

[11] Woulfe and Michael White took the Government of Ireland to the European Court of Human Rights due to a long delay in their professional fees being discharged at the tribunal.

[16] In 2015, he represented John Perry in the High Court in a challenge against Fine Gael decision to drop him as a general election candidate.

[20] He was appointed as Attorney General in June 2017 on the nomination of Taoiseach Leo Varadkar, at the formation of the 31st Government of Ireland, succeeding Máire Whelan.

[21] In 2018, he described the Judicial Appointments Commission Bill 2017, which had been promoted by Minister for Transport, Tourism and Sport Shane Ross, as "a dog’s dinner".

[22][23][24][25][26] The Bill reached the final stage of debate in Seanad Éireann and was subject to a series of amendments which delayed its progression through the Oireachtas.

[38] In July 2020, he was nominated by the Government to fill a vacancy on the Supreme Court of Ireland following the retirement of Mary Finlay Geoghegan.

[39] Serving judges made expressions of interest to the Minister for Justice Helen McEntee, but only Woulfe's name was brought to cabinet.

[44] The dinner was subject to media and public controversy due to it being possibly contrary to government guidelines regarding COVID-19, and to the spirit of restrictions at the time.

[48] As matters played out over several months, a former Chief Justice concluded that attendance had been an error but not a breach of law or guidelines, the existing judges of the Supreme Court apparently concluded that the issue had caused "significant and irreparable" damage to the Court, and a criminal trial accepted that the organisers had made a reasonable effort to comply with the rules as understood.

The Courts Service announced on 24 August 2020, that former Chief Justice Susan Denham was appointed to review his attendance at the dinner and to consider possible new guidelines and make recommendations.

[51] Woulfe and Collins met with Denham and her legal adviser Shane Murphy on 8 September 2020 in Green Street Courthouse.

[57] The 15 October meeting was subsequently cancelled on account of the Chief Justice receiving a "cogent medical report" from Woulfe describing an illness.

[61] Woulfe reiterated his apology, asked the Chief Justice not to publish their letters and stated that he would not resign, citing judicial independence, his belief that he had not breached any law or guidelines and that there had been a "shift in the goal posts".

[70] Woulfe's first sitting on the Supreme Court occurred on 4 February 2021, to discuss application for leave to appeal as part of a three-judge panel.