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Brandon O'Neil



ONeil Brandon
Brandon O'Neil



Brandon focuses on complex cross-border regulatory investigations, financial crime matters and litigation, with particular experience representing financial institutions. He advises clients on a broad range of issues such as insider trading, anti-money laundering, asset tracing and judgment enforcement, fraud and bribery.

Brandon represents both institutions and individuals in cross-border investigations involving a range of regulators in the U.S. (DOJ, SEC, CFTC), Europe (UK FCA, SFO) and Asia. He has particular expertise in investigations involving insider trading, money laundering, market manipulation, bribery and fraud. In addition to England and Wales, Brandon is admitted to the Bar of the State of New York and worked for a number of years in A&O’s New York office. Given the critical importance of U.S. law in contentious regulatory investigations and the far-reaching impact of U.S. authority-led investigations, this dual-experience brings valuable insight and experience to clients when they experience multi-jurisdictional, multi-agency investigations. Brandon also has substantial experience in submitting and defending private criminal complaints in continental European jurisdictions.

Brandon’s litigation practice focuses on cross-border fraud, asset tracing and judgment enforcement matters. Brandon’s dual New York and English qualification, together with his extensive experience litigating in various jurisdictions around the world, brings the cross-border outlook needed to successfully pursue (or defend) complex cases of this type. In addition to experience in such cases in the UK courts, Brandon has represented clients in numerous such enforcement cases across Europe, the U.S., the Caribbean and Asia, seeking to recover a broad range of assets ranging from art to real estate.

News & insights

Sun peering behind modern skyscrapers on the skyline

Publications: 10 SEPTEMBER 2021

Lessons learned on taking security in a commodity finance transaction

In the first article of our Legal Watch Series with Global Trade Review (GTR), Catherine Lang-Anderson and Brandon O’Neil discuss the steps banks can take to manage risk when taking security in a…

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High rise buildings from the bottom

Blog Post: 08 JULY 2021

UK corporate criminal liability reform

The UK Government has asked the Law Commission to review the law on corporate criminal liability and propose options for reform. Supporters of reform will use recent failures of the UK Serious Fraud…

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Publications: 02 SEPTEMBER 2020

Direct access: a sea change in data gathering in U.S./UK criminal investigations

A new UK/U.S. bilateral agreement for accessing electronic data in cases of serious crime (the Agreement), which was negotiated and released in autumn 2019, has entered into force.

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Blog Post: 08 JULY 2020

Direct access – a sea change in data gathering in UK/U.S. criminal investigations

A new UK/U.S. bilateral agreement for accessing electronic data in cases of serious crime, which was negotiated and released in autumn 2019, is about to enter into force.

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Allen & Overy LLP
One Bishops Square
E1 6AD

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Admitted: Bar of the State of New York, 2009

Admitted: U.S. District Court, Southern District of New York, 2009  


J.D., Columbia Law School, 2008

M.A., University of Wyoming, 2004 

B.A., University of Wyoming, Phi Beta Kappa, 1999