Owen O'Sullivan


+353 1 639 5368
owen.osullivan@williamfry.com vCard

Owen O'Sullivan is Head of William Fry’s Litigation & Dispute Resolution Department.  He specialises in commercial disputes, particularly shareholder and investment disputes, as well as disputes in the financial sector. He has been involved in many high profile property disputes and has product liability defence experience in the pharmaceutical, energy drink, motor and tobacco sectors.

Recent significant work includes advising:

  • Horizon Sports Management on the defence of  the claim brought against it by golfer Rory McIlroy and the prosecution of its counterclaim.
  • Alternative Advantage plc in Commercial Court proceedings for the return of over €100m sub-custodied to Bernard Madoff
  • Tesco on its contractual dispute relating to the development of a new district centre store at Carrickmines.
  • Davy Stockbrokers both on its successful Supreme Court challenge to a decision by the Financial Services Ombudsman and ongoing defence of Credit Union litigation
  • DCC plc through its High and Supreme Court insider dealing action brought by Fyffes plc and the subsequent Inspectorship process

Owen served as a member of the Law Society’s Litigation Committee for six years and is currently a member of the International Bar Association, the Steering Committee of the Commercial Litigation Association of Ireland and DRI Europe.

Owen is consistently ranked as a leading lawyer by international legal directories

In Chambers Global 2017 Owen receives plaudits from a range of market commentators, describing him as an "excellent corporate litigator" and "a very astute operator" who has "very tactical and good commercial judgement" and  "very well regarded and a good litigator." 

Owen is recognised in Best Lawyers 2018 under 'The Best Lawyers in Ireland' for work in Arbitration & Mediation, Bet-the-Company Litigation, Litigation and Product Liability Litigation 

Chambers Global 2016 describe him as a litigator and dispute resolution specialist with an exceptional reputation, including sound knowledge and experience of insurance disputes. Clients praise him as "quickly able to make decisions on how to handle certain situations, taking into account all stakeholders that may be affected." Other describe him as a "very astute guy with really reliable intuition in court."

Chambers Europe, 2015 describe Owen as "a superb lawyer - he's patient, doesn't lose his cool or display any signs of stress, and always seems to have our interests at the fore." While Legal 500 EMEA, 2015 state that he provides "direct and definitive advice".

Department head Owen O'Sullivan is described by sources of Chambers Europe, 2014 as "very pragmatic and has a value-for-money approach".  Sources regard Owen as "pragmatic and a deal maker. He is a great litigator.

According to sources of Chambers Global, 2013, Owen 'really knows his stuff, is always well briefed, and is efficient and easy to deal with.'  In Legal 500 EMEA, 2013, Owen is described as 'very bright’ and ‘an insightful strategic thinker’. 



Legal 500 2017

Whos Who Legal