Colahan, John D.

John D. Colahan

Retired Partner

John Colahan retired from the partnership on December 31, 2020. He was based in Latham & Watkins' London office and divided his time with the Brussels office.

He was a member of the Global Antitrust & Competition Practice, having previously been a Legal Advisor at the UK Cabinet Office and international competition law counsel at The Coca-Cola Company. John represented clients before the European Commission, national authorities in Europe and internationally, and conducted litigation in the European courts and numerous national courts. He has advised on a variety of international antitrust matters, including structuring and implementation of international mergers, acquisitions, and joint ventures; cartel enforcement; single firm conduct; and compliance counselling. As a Cabinet Office Legal Advisor to the European Secretariat, Mr. Colahan was responsible for policy coordination with the Treasury and other departments on financial services.    

Mr. Colahan regularly lectures on a range of international antitrust and compliance issues.


  • Postgraduate Diploma in EU Competition Law, King's College London, 1998
  • LSF, College of Law, Guildford, 1990
  • Standard Graduate Officer Course, Royal Military Academy Sandhurst, 1986
  • LLB, University of Nottingham, 1985