Mark Sanfey is an Irish judge and lawyer who has served as a Judge of the High Court of Ireland since December 2019. He previously practiced as a barrister specialising in insolvency and bankruptcy law.

Sanfey was educated at Trinity College Dublin and trained to be a barrister at the King's Inns.^[1][2]

He became a barrister in 1987 and became a senior counsel in 2004.^[1] Sanfey specialised in aspects of insolvency law while in practice, including cases involving examinership, bankruptcy, receivership, and liquidation.^[3][4][5][6] He represented the former chair of Anglo Irish Bank Seán FitzPatrick in bankruptcy proceedings in 2010.^[7]

His practice also extended to other commercial litigation, including contractual disputes.^[8] He appeared for Michelle Rocca in 2015 in the High Court relating to a land dispute with her neighbour.^[9]

He acted for businessman Richard Lynn at the Mahon Tribunal.^[10]

Outside of practice, he was a founding member of the Construction Bar Association of Ireland, for which he was chairman between 2013 and 2018.^[1][11] In 1991, he co-authored "Bankruptcy Law and Practice in Ireland", with a second edition published in 2010.^[12][13]

Sanfey was appointed to the High Court of Ireland in December 2019.^[14] He has heard cases involving bankruptcy, insolvency law, injunctions, judicial review, and professional misconduct.^{[15][16][17][18][19]} He replaced Denis McDonald as the High Court's designated judge hearing personal insolvency matters.^[20] As of 2021, he is the judge appointed to oversee arbitration cases in the High Court.^[21]