John Greenfield is a consultant for the dispute resolution and litigation group of Carey Olsen in Guernsey where he was previously senior partner.

John undertakes the complete range of major litigation and advocacy work including asset tracing, multi-jurisdictional disputes and commercial and trust litigation. John has been counsel in many of the major litigation cases before the Royal Court of Guernsey and the Guernsey Court of Appeal and is one of the few Guernsey advocates to have appeared as counsel in the Privy Council. He has been lead counsel in many ground-breaking trust litigation cases. In the case involving a Tchenquiz Family Trust he was successful in obtaining a judgment in favour of creditors of the trust against the trust assets and in a subsequent judgment obtained an order of the Guernsey Court putting the trust assets into receivership.

John was a member of the committee which completely overhauled Guernsey's civil procedure in 2008 and is part of the new review committee. He has been the Guernsey member of the UK Fraud Advisory Panel since 2001. He is a founder member of Fraudnet, a body of the world's leading fraud lawyers set up by the International Chamber of Commerce. He is also a member of the Association of Contentious Trust and Probate Specialists (ACTAPs) and is a Notary Public. John was the first elected as head of the Guernsey Bar in November 2008 and was re-elected to the role in 2010. In 2014 he was awarded ACTAPs 'Offshore Contentious Lawyer of the Year Award'. John was listed in the Who's Who Legal: Asset Recovery report for 2023 and regularly features in Who's Who Legal: Thought Leaders Global Elite. He is also ranked as a leading individual in Guernsey by the Legal 500 UK and Chambers Global legal directories.

John was enrolled as a Solicitor in England in 1975 where he was a partner in a law firm before moving to Guernsey in 1980. After working as in-house counsel and trust manager for an international merchant bank, John qualified as a Guernsey advocate with the firm and in the same year became a partner in 1986.

• Fraud, Asset Tracing & Recovery 2023 – Guernsey (Commercial Dispute Resolution, CDR)
• Five chapters authored for Commercial Dispute Resolution (CDR) Fraud Asset Tracing and Recovery 2023