Mark D. Hopson

MARK HOPSON is a trial lawyer who focuses his practice on government enforcement actions and other high stakes litigation. He served on Sidley’s Management Committee for 13 years and its Executive Committee for 19 years, and formerly co-led the global Litigation practice. He has won the National Law Journal’s “Defense Verdict of the Year” and is a Fellow of the American College of Trial Lawyers.

“Mark is the full package. He has an incredible breadth of experience and is extremely smart on factual and legal issues. He is great in the courtroom.”
Chambers USA 2022

In addition to criminal and civil trial cases, Mark regularly represents clients in connection with congressional investigations, internal investigations, and other enforcement matters. The scope of Mark’s practice is reflected in his trial court victories and other representations, including:

• Lead trial counsel for Chevron in successful pursuit of contribution claims against the United States in connection with environmental remediation of former mining site.
• Successfully defending Bayer against a contempt action filed by the United States that sought hundreds of millions of dollars and alleged that Bayer was unlawfully marketing its probiotic product, Phillips’ Colon Health. After a two-week trial, the Court denied the government’s motion in its entirety. Mark was recognized as “Litigator of the Week” for his trial victory in United States v. Bayer by The AmLaw Litigation Daily.
• Representing the former CEO of Freddie Mac, Richard Syron, in response to congressional subpoenas, an SEC enforcement action in the Southern District of New York, and multiple class action securities cases. As The New York Times wrote in an article describing the settlement with the SEC: “Now a case that began with such fanfare has ended with a whimper.” 
• Obtaining an acquittal at trial of Tyson Foods, Inc. on a 36-count indictment charging conspiracy to violate federal immigration laws and seeking criminal forfeiture of over US$100 million, a result that The National Law Journal identified as the “Defense Verdict of the Year.”

“Mark has wisdom in spades.”
Chambers USA 2024

Mark has been recognized by Chambers USA for Litigation: White-Collar Crime & Government Investigations in Washington, D.C. (2009–2025), where he is noted as “very strategic and on point, and always surveys the whole field” (2021). Mark has also been named a “Life Sciences Star” by LMG Life Sciences for his work in White-Collar/Government Investigations (2019–2023). In 2015, Mark received Law360’s “White Collar MVP” award and The National Law Journal’s “White Collar Trailblazer” award. He has been ranked as a “Litigation Star” in Washington, D.C. by Benchmark Litigation (2022–2025), and has been repeatedly recognized in publications such as PLC Dispute Resolution (Cross-border White Collar Investigation Handbook) and Legal 500 United States. Mark has also been named by Super Lawyers magazine as one of the “Top 100: Washington, D.C. Super Lawyers,” a recognition based on a vote of peers (2011–2015, 2018, 2022, 2024). Washingtonian magazine has continuously included Mark in its roster of “Washington, D.C.’s Top Lawyers,” naming him to its “Top Lawyers Hall of Fame” in 2022. Since 2005, he has been recognized by The Best Lawyers in America in Bet-the-Company Litigation, White Collar Criminal Defense, and Regulatory Enforcement Litigation.

A sampling of Mark’s representative clients and matters includes:

• Merck & Co., Inc. et al. v. Merck KGaA — Representing Merck & Co. in a trademark and breach of contract case involving the use of the name “Merck” in the United States.
• Federal Trade Commission v. Fleetcor Tech., Inc. — Lead trial counsel for FleetCor Technologies in Federal Trade Commission case challenging fuel card marketing practices.
• State of Oklahoma v. Tyson Foods — Representation Tyson Foods, Inc. in one of the largest environmental cases tried in 2010. The state sought up to US$1.6 billion in damages and injunctive remedies in connection with a claim under CERCLA, RCRA and state law alleging pollution of a million-acre watershed. The case was tried between September 2009 and February 2010 in the Northern District of Oklahoma. Tyson prevailed on all of the state’s monetary claims, which were dismissed by the court. The trial court also dismissed the State’s CERCLA and RCRA claims, along with some of the state’s nuisance and statutory claims.
• United States v. Johnson & Johnson — Representation of a pharmaceutical company in connection with False Claims Act complaint brought by DOJ Civil Division in connection with complex regulatory claims involving safe harbors under the Anti-Kickback Statute. 
• Pickett v. IBP — Representation of the nation’s largest beef packing company in a jury trial of class action claims seeking over US$2 billion in damages on the theory that supply contracts had anticompetitive effect on beef cattle prices. Trial court’s order of judgment as a matter of law affirmed by Eleventh Circuit. 
• World Bank — Representation of International Bank for Reconstruction and Development in litigation and internal investigations relating to fraud and embezzlement claims and related asset recovery litigation. 
• In re: BCCI Litigation — Representation of the Government of Dubai in connection with claims arising out of litigation surrounding Bank of Credit and Commerce International. Also represented the Government of Dubai in other civil and commercial litigation, including fraud, contract and employment-related claims. 
• Washington Sports Ventures v. Jack Kent Cooke, Inc. — Representation of the estate of the former Washington Redskins owner in defense of fraud, breach of fiduciary duty and contract claims brought by a failed bidder for the team. Summary judgment granted for estate. 
• Haft v. Haft — Representation of company, director and officers in two-month jury trial involving corporate control, fraud and fiduciary duty claims. 
• Wen Ho Lee — Representation of scientist at Los Alamos National Laboratory in connection with Privacy Act claims, libel litigation and criminal indictment. 
• United States v. Sinskey — Representation of a senior corporate official in environmental crime jury trial. 
• United States v. Mitchell — Representation of Smithsonian scientist in criminal tax fraud jury trial.

Mark is a member of the District of Columbia Committee of the American College of Trial Lawyers and a Fellow of the American Bar Foundation. He has also served as a trial practice instructor and an adjunct professor at the Georgetown University Law Center.