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.

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. John is listed as a Global Elite Thought Leader by Who's Who Legal for Asset Recovery.