William O'Brien

Practice Areas

Will O’Brien is Global Co-Head of International Arbitration at the firm. For more than 25 years, he has guided clients through high-stakes international arbitration, litigation, and global judgment and arbitral award enforcement. Will develops global disputes strategies for clients to achieve their business goals. As a distinguished first-chair counsel, he advocates for clients in courts and arbitral institutions across six continents in financial services, aerospace and defense, manufacturing, energy, transportation, and technology. In his role on the firm’s Global Board of Directors, Will provides strategic advice and insights on how best to serve clients across regions and sectors.

Will is ranked “Band 1” by Chambers USA for international arbitration, where clients say “We prize Will above all others” and describe him as “the most universal and versatile attorney I have ever worked with” possessing “everything you can ask for in outside counsel.” He “combines depth of knowledge and commercial awareness with international experience and cultural empathy and understanding, without ever discounting effectiveness and efficiency.”

Clients value Will’s practical, business-oriented approach, immersing himself in their immediate issues, while never losing sight of their long-term strategic goals. He works with general counsel, industry and political leaders, journalists, and academics to study ways to mitigate and manage corporate geopolitical risk, particularly in emerging markets. Through a six-year appointment to the ICC’s Commission on Arbitration and ADR, he helps shape rulemaking and policy in international disputes. Where appropriate, he leverages the strength of practitioners in government relations, public affairs, and communications to achieve results for clients – especially in high-profile, political, and hostile environments.