Owen O'Sullivan

Consultant

Owen was Managing Partner of William Fry from 2020 until November 2024. Prior to that he was Head of our Litigation & Investigations Department. He is now a Consultant in Litigation & Investigations and from 1 November 2025, also takes up a role as a part-time Commissioner of the Law Reform Commission.

Owen O'Sullivan

Owen 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.

Owen specialises in large scale commercial disputes, particularly shareholder and investment disputes, as well as disputes and advisory work in the financial sector. He has considerable experience in regulatory proceedings across many industry sectors as well as in Tribunals, Inquiries and Investigations.

Owen served as a member of the Law Society’s Litigation Committee for six years and has been a member of the International Bar Association for many years. He was a founding member and subsequently Chair of the Commercial Litigation Association of Ireland. He is also an IMI accredited mediator.

 

2026 legal 500 EMEA
2025 Legal 500 EMEA
2024 Chambers Global
2023 Chambers Europe

Practice Areas

Corporate Disputes
Regulatory Investigations
Litigation & Investigations
White Collar Crime & Investigations

Related Knowledge

View All 
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Press Release

Owen O’Sullivan Appointed as Member of the Law Reform Commission

William Fry is delighted to confirm that Owen O'Sullivan, former managing partner has been appointed as a Commissioner of the Law Reform Commission.

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Consultant
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Article and Insights

Court Awards €11m for Breach of Fiduciary Duties

Fiduciary duties owed to company despite defendant not being a direct employee.

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Consultant
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Article and Insights

William Fry Wins Irish Patent Litigation Firm of the Year at the Global IP Awards

William Fry is delighted to have been awarded the prestigious title of Irish Patent Litigation Firm of the Year at the Global IP Awards 2024.

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Consultant
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Article and Insights

William Fry Ranked Ireland’s Most Innovative Law Firm

William Fry has been ranked as Ireland’s most innovative law firm and the 34th most Innovative European law firm by the Financial Times Innovative ...

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Consultant
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Article and Insights

William Fry Announces Stephen Keogh as Next Managing Partner

William Fry is pleased to announce the appointment of Stephen Keogh as the firm’s next Managing Partner, effective November 2024.

Liam McCabe
Chairperson
Liam McCabe
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Article and Insights

William Fry Announces Nine New Partners

New Partners across Asset Management & Investment Funds, Litigation & Investigations, Real Estate, and Technology.

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Article and Insights

William Fry Responsible Business Annual Report 2021

William Fry's Responsible Business Annual Report for 2021 details the extensive work undertaken by the firm to work responsibly and give back to ou...

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Consultant
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Appointment

William Fry Announces Five Senior Appointments

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Consultant
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Events

Almost 2/3 of people with disability working within the legal sector have not shared their disability status at work

The inaugural event of the disAbility Legal Network event is hosted by William Fry.

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Consultant
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Awards

William Fry Earns Top Irish Corporate Social Responsibility Accolade

Owen O’Sullivan
Consultant
Owen O’Sullivan
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