Speaker details

30th Annual Competition Conference

4 Sep - 5 Sep 2026

The St Regis Florence, Florence, Italy

Speaker information

Sonia Pfaffenroth

Biography

Sonia Kuester Pfaffenroth is a partner in Sullivan & Cromwell’s Litigation Group and a member of the Antitrust Group. She represents clients in complex U.S. and international antitrust matters, including federal and state civil antitrust litigation, government investigations and cartel matters. Her practice also includes merger reviews, antitrust compliance and training, and day-to-day counseling on pricing, marketing, distribution, contracting, trade association participation and R&D collaborations. Before returning to private practice, Sonia held senior leadership positions in the Antitrust Division of the U.S. Department of Justice. Most recently, she served as Deputy Assistant Attorney General for Civil and Criminal Operations. In that role, she supervised civil and criminal antitrust enforcement efforts and coordinated with antitrust and competition law enforcement agencies worldwide. She also had responsibility for the Division’s international program, policy initiatives and competition advocacy efforts.