27 Apr 2026
John Liolos Returns to Sullivan & Cromwell as Partner in Litigation and Criminal Defense & Investigations
"John Liolos joins Sullivan & Cromwell as partner in its Litigation and Criminal Defense & Investigations Groups in New York, focusing on white‑collar enforcement and regulatory matters including securities, commodities, healthcare, insider trading and crypto fraud."
Mr. Liolos returns to Sullivan & Cromwell after five years with the U.S. Department of Justice’s Criminal Division Fraud Section (Market, Government and Consumer Fraud Unit), where he served as a Trial Attorney. He joins S&C as a partner and will work in the firm’s litigation and white‑collar enforcement practices.
As a federal prosecutor, Mr. Liolos first‑chaired white‑collar criminal prosecutions and advised on complex regulatory and enforcement matters, often coordinating with government regulators including the SEC, CFTC and FINRA. His experience covers securities and commodities fraud and manipulation, healthcare and government program fraud, insider trading, public corruption and bribery, investment fraud and cryptocurrency fraud.
While at the DOJ he led the prosecution of Wall Street director‑level traders for spoofing, first‑chaired a trial conviction for pandemic relief fraud, and obtained multiple convictions in insider trading and commodities manipulation cases. He represented the United States on appeals before the U.S. Courts of Appeals for the Fifth and Tenth Circuits, supervised complex investigations and trial convictions, and was awarded the Assistant Attorney General’s Award for Distinguished Performance. Mr. Liolos earned his J.D., magna cum laude, from Boston College Law School, holds an M.A. in Public Law from Columbia University and a B.A. from Boston College, clerked for Judge Robert Bacharach (U.S. Court of Appeals for the Tenth Circuit) and Chief Judge Matthew Brann (U.S. District Court for the Middle District of Pennsylvania), and is a member of the New York Bar.