Jeffrey H. Knox

Jeffrey Knox, former head of the U.S. DOJ Fraud Section, is Co-Managing Partner of Simpson Thacher’s Washington, D.C. office and Global Co-Head of the Firm’s Government and Internal Investigations Practice. Jeff represents multinational corporations and independent board committees in high-stakes criminal and civil investigations by the DOJ, SEC, State Attorneys General, and other federal and state enforcement regulators. He also represents senior executives and government officials who are subjects of enforcement investigations.  

Jeff has twice been recognized by Law360 as one of five “MVP” white collar lawyers in the United States (2025 and 2021), and in 2024 was named in Financier Worldwide’s global list of 10 white collar “Power Players” (2024). He is recognized as a Band 1 lawyer by Chambers USA and Chambers Global (FCPA), as a “Leading Lawyer” by The Legal 500, and a “Litigation Star” by Euromoney’s Benchmark Litigation, where sources note him as “one of the best lawyers in the country,” “spectacular, hardworking,” “brilliant with an incredible depth of knowledge,” and “a master strategist with a unique insight into the way the DOJ works,” who “understands cases from multiple different dimensions.” Jeff is a fellow of the Litigation Counsel of America, a member of the Law Board at Northwestern University Pritzker School of Law (his alma mater) and previously served on corporate compliance and enforcement advisory boards at New York University School of Law and the American Law Institute.

Jeff has advised some of the world’s leading companies in the financial services, private equity, energy, life sciences, technology and cryptocurrency industries in navigating criminal and civil investigations relating to the federal securities and commodities laws, anti-corruption and anti-money laundering statutes, the False Claims Act, antitrust laws, and economic sanctions and other trade control regulations. Jeff represents companies subject to government and court-mandated monitorships, and has served as a government-appointed independent compliance consultant. Prior to joining the Firm, Jeff served as a federal prosecutor for more than a decade, including as the Chief of the DOJ’s Fraud Section in Washington, D.C., and before then, as the Chief of the National Security Section of the U.S. Attorney’s Office for the Eastern District of New York. He has twice been profiled in the New York Times for his work as a prosecutor.

Jeff's representative matters include:

Company Representations

• Global financial institution in investigations by the DOJ, SEC, CFTC and federal banking regulators relating to anti-money laundering and economic sanctions controls
• Multinational technology company in DOJ False Claims Act investigation
• Audit committee of a Chinese automotive energy company in an investigation into possible corruption and bribery issues in China
• Energy trading firm in DOJ and CFTC investigations relating to alleged corruption and market manipulation
• Private equity firm in DOJ criminal and civil investigations of alleged antitrust violations
• Global hedge fund in SEC investigation of trading practices
• Global financial institution in a multi-regulator investigation related to the alleged offering of unregistered securities
• Global oil company in DOJ investigation of alleged environmental crimes
• India-based multinational conglomerate relating to DOJ investigation of potential fraud
• SEC-mandated Independent Consultant to global life sciences company, relating to FCPA internal control failures
• Global financial institution in DOJ, SEC, and CFTC investigations of alleged market manipulation and spoofing in derivatives markets
• Special board committee of a financial services firm in an independent review of allegations relating to compliance with a regulatory Consent Order with the CFPB
• A global securities firm in connection with a CFTC investigation into a cryptocurrency exchange and alleged evasion of CFTC regulatory requirements 
• U.S.-listed South American construction company in an SEC FCPA investigation relating to potential corruption issues and internal control failures
• U.S. technology company in resolution with the DOJ relating to alleged accounting and securities fraud violations
• Multinational hedge fund in DOJ investigation of alleged insider trading
• Leading global pharmaceutical manufacturer in FCPA investigation focused on alleged misconduct in multiple jurisdictions
• Board Committee of international cruise line in connection with environmental-related corporate monitorship

Individual Representations

• Senior executive of a financial services firm in obtaining the dismissal of a CFPB lawsuit of alleged deceptive practices
• Former executive of an aerospace and defense company in connection with a DOJ investigation into FCPA and compliance issues
• Senior executive of cryptocurrency firm in DOJ, SEC and NYAG investigations into alleged securities and investment fraud
• Senior member of Board of Directors of a global financial institution in a DOJ criminal investigation relating to alleged collusion among competitors
• Former executives of a Swiss bank in a DOJ investigation related to alleged tax fraud
• Executive of international airline manufacturer in DOJ FCPA investigation
• Chairman and CEO of U.S.-listed educational company in DOJ and SEC corruption investigation
• Acting Secretary General of FIFA in DOJ investigation relating to the global corruption scandal
• General Counsel of global financial institution in DOJ criminal antitrust investigation
• Senior political fundraiser in DOJ criminal FARA investigation
• Senior derivatives trader in DOJ investigation of alleged spoofing and market manipulation