Ms Deirdre O'Mahony > Arthur Cox > Dublin, Ireland > Lawyer Profile

Arthur Cox
D02 T380
Deirdre O'Mahony photo

Work Department

Litigation, Dispute Resolution and Investigations


Deirdre is a partner in the Litigation, Dispute Resolution and Investigations Group. She specialises in investigations, commercial and regulatory disputes and corporate / white collar crime.

Deirdre advises a range of domestic and international clients on significant commercial and regulatory disputes, investigations (internal, regulatory, cross-border and criminal) and criminal prosecutions. Deirdre is a founding member of the Ireland Chapter of the Women’s White Collar Defence Association (WWCDA), the Irish representative member of the European Criminal Bar Association Anti-Corruption Europe (ACE) Working Group and Committee member of the Health and Safety Lawyers’ Association of Ireland. Deirdre co-authored the Ireland chapter of the White-Collar Crime Guide 2019 for Chambers and Partners and the ACE Country Report for Ireland on anti-bribery / corruption. Deirdre is also an accredited CEDR mediator.


Admitted as a Solicitor, 2009


Law Society of Ireland; Founding member, Ireland Chapter of the Women’s White Collar Defence Association (WWCDA); Irish representative member, ECBA Anti-Corruption Europe (ACE) Working Group; Committee member, Health and Safety Lawyers’ Association of Ireland (HSLAI)


Certificate in Local Government Studies, IPA/UCD, 2012
LL M, NUIG / Queen’s University, Belfast, 2006
LL B, University of Limerick, 2004

Lawyer Rankings

Ireland > White-collar crime

The ‘excellent‘ team at Arthur Cox is active in the commercial and corporate sphere, advising on shareholder and boardroom disputes and investigations. The team also has extensive experience in high-profile statutory inquiries across a range of sectors, and international investigations involving regulatory authorities in the US and the EU. The practice is led by Joanelle O’Cleirigh, who has a strong reputation for representing clients in public inquiries; Greg Glynn, who has extensive experience in investigations by foreign regulators; and Richard Willis, whose practice covers internal, regulatory and financial crime investigations. Deirdre O’Mahony is also noted for her expertise in regulatory investigations in the financial sector.