Duncan Speller

Duncan Speller is co-chair of the International Disputes Division of Duane Morris’ Trial Practice Group, representing clients in high-value and complex international arbitration and English High Court litigation.

Mr. Speller is an English-qualified barrister with approximately twenty five years of experience of international disputes, frequently as lead advocate in high-stakes disputes with hundreds of millions or billions of dollars in dispute. Mr. Speller has represented clients in more than two hundred arbitrations sited in civil and common law jurisdictions including England, New York, California, Texas, Brazil, Hong Kong, Singapore, Dubai, France, Switzerland, Spain, Sweden, Denmark, Norway, Austria and Germany.

Mr. Speller works with clients in the aviation, oil and gas, mining and resources, insurance and reinsurance, private equity, telecommunications, technology, banking industries. He has represented companies in matters regarding transfer fees, production sharing contracts, mergers and acquisitions, aircraft lease agreements and competition law.

He has served as an arbitrator and as an emergency arbitrator for numerous institutions. He is ranked by Chambers UK (2025) for International Arbitration, and the Legal 500 UK (2025) also recognized him as a “Leading Individual.” Clients reported to Chambers that he has "flawless judgement and a very enviable work ethic" and is "very persuasive, tactical and is a great presenter."

Mr. Speller earned his B.C.L. (Distinction) from the University of Oxford and his MA(Hons) in Law (First Class) from the University of Cambridge.

Mr. Speller regularly writes and speaks in the field of international arbitration and has delivered lectures at some of the World’s leading academic institutions including the University of Cambridge, the University of Harvard and Tsinghua University (China).