William P. Barnett (born 1958) is an American organizational theorist, and is the Thomas M. Siebel Professor of Business Leadership, Strategy, and Organizations at the Stanford Graduate School of Business. He is the BP Faculty Fellow in Global Management; Senior Fellow, Woods Institute for the Environment at Stanford; Director of the Center for Global Business and the Economy; Director of the Business Strategies for Environmental Sustainability Executive Program; and Codirector of the Executive Program in Strategy and Organization.