Stephen Jagusch KC

Stephen Jagusch KC is a partner at Quinn Emanuel Urquhart & Sullivan LLP and Global Chair of the firm's International Arbitration Practice, based in London. He has been named Arbitration Lawyer of the Year in the United Kingdom at the Corporate INTL Global Awards 2025, an award that reflects his position among the most highly regarded international arbitration practitioners working in the market.

Jagusch specialises in international commercial and investment treaty arbitration, having served as adviser and advocate in dozens of ad hoc and institutional arbitrations across many jurisdictions. He has acted as lead counsel in numerous investment treaty cases, a significant number of them involving sovereign states or multinational organisations, where the stakes for the parties are frequently substantial and the legal and factual issues highly complex. His practice combines the roles of counsel and advocate, and he is recognised as a formidable presence in hearings, described by leading directories as one of the most impressive advocates around and a masterful cross-examiner.

In addition to acting as counsel, Jagusch sits regularly as an arbitrator, serving as chair, sole arbitrator or co-arbitrator in disputes referred to him by the parties. This dual perspective, appearing before tribunals and sitting on them, gives him an unusually rounded understanding of how arbitrations are argued and decided, and informs the strategic judgement he brings to the cases he leads. He is a Fellow of the Chartered Institute of Arbitrators and a member of the Board of Trustees of the Bahrain Chamber for Dispute Resolution, reflecting his engagement with the institutions that underpin international arbitration.

His standing is consistently confirmed by the leading legal directories. He has been ranked in Band 1 for international arbitration by Chambers UK and holds Hall of Fame status in the Legal 500 for both international arbitration and public international law. He has been named among the best lawyers in the United Kingdom for international arbitration and listed among the leading global litigators, recognition that spans commercial disputes, investment treaty work and public international law. Before joining Quinn Emanuel he chaired the global international arbitration practice of another leading international firm, and he took silk as King's Counsel. London is one of the world's leading centres for international arbitration, the preferred forum for resolving many of the largest cross-border commercial and investment disputes. Arbitration offers parties a neutral, confidential and enforceable means of resolving disagreements that span different legal systems, and success in this field depends on advocates who combine deep legal knowledge with tactical skill and persuasive presentation. Investment treaty work, in which private investors bring claims against states, adds a further layer of public international law and political sensitivity, and Jagusch's practice sits at the heart of this world, encompassing both commercial and investment treaty arbitration and the roles of counsel and arbitrator alike.

Leading the international arbitration practice of Quinn Emanuel, a firm known for high-stakes disputes work, Stephen Jagusch KC continues to act in some of the most significant commercial and investment arbitrations before international tribunals. His recognition as Arbitration Lawyer of the Year in the United Kingdom at the Corporate INTL Global Awards 2025 underscores the reputation he has built as a leading counsel, advocate and arbitrator in the field.