NEW YORK (APRIL 27, 2026) – Sullivan & Cromwell LLP announced today that John Liolos has rejoined the firm as a partner in its Litigation and Criminal Defense & Investigation Groups, resident in its New York office. Mr. Liolos rejoins S&C after five years with the U.S. Department of Justice’s Criminal Division’s Fraud Section. As a federal prosecutor first-chairing white collar criminal prosecutions, Mr. Liolos returns with extensive experience advising on complex regulatory and enforcement matters, often working in parallel with government regulators including the SEC, CFTC and FINRA.
“We’re delighted that John is returning to S&C after five years at DOJ,” said Sullivan & Cromwell Co-Chairs Robert Giuffra and Scott Miller. “John is an exceptional criminal defense litigator with a proven track record in and out of the government. His addition builds on the strength of our white-collar team and broader Litigation Group.”
Mr. Liolos’s experience spans a wide range of complex litigation matters, including securities and commodities fraud and manipulation, healthcare and government program fraud, insider trading, public corruption and bribery, investment fraud and cryptocurrency fraud.
“John brings a great combination of private-sector and government experience across securities and commodities fraud and manipulation, healthcare and government program fraud, insider trading, public corruption and bribery, investment fraud and cryptocurrency fraud,” said Nicolas Bourtin, Managing Partner of S&C’s Criminal Defense & Investigations Group and a co-head of the Firm’s FCPA and Anti-Corruption Group. “We’re excited to welcome him back.”
Prior to joining S&C, Mr. Liolos served as a Trial Attorney within the DOJ’s Criminal Division Fraud Section (Market, Government and Consumer Fraud Unit), where he was awarded the Assistant Attorney General’s Award for Distinguished Performance. He led the prosecution of Wall Street director-level traders for spoofing, first-chairing a trial conviction for pandemic relief fraud and obtaining multiple convictions for insider trading and commodities manipulation schemes. Mr. Liolos has represented the United States on appeals before the U.S. Court of Appeals for the Fifth and Tenth Circuits, supervised complex investigation and trial convictions and supported agencies across the federal government.
“I’m happy to be returning to Sullivan & Cromwell in New York,” said Mr. Liolos. “I’m looking forward to once again working with our talented team on issues at the cutting edge of enforcement and regulatory activity.”
Mr. Liolos earned his J.D., magna cum laude, from Boston College Law School, an M.A. in Public Law from Columbia University, and his B.A. from Boston College. He clerked for Judge Robert Bacharach on the U.S. Court of Appeals for the Tenth Circuit, and Chief Judge Matthew Brann on the U.S. District Court for the Middle District of Pennsylvania. He is a member of the New York Bar.
About S&C's Criminal Defense & Investigations Group
S&C’s Criminal Defense & Investigations Group is a leader in resolving cases on the cutting edge of enforcement and regulatory activity. The Firm has played a leading role in virtually every major U.S. law enforcement initiative of the past 25 years, and our lawyers have handled more than 125 criminal trials in federal and state courts. S&C’s lawyers routinely appear before all major enforcement agencies and have extensive experience handling multiagency investigations and cross-border enforcement actions involving white collar, criminal defense and regulatory issues.
About Sullivan & Cromwell LLP
Sullivan & Cromwell LLP is a leading global law firm that advises on major domestic and cross-border M&A, significant litigation and corporate investigations, finance and corporate transactions, and complex antitrust, regulatory, tax and estate planning matters. Our firm’s hallmarks are the highest-quality independent advice and intense dedication to solving client problems. Founded in 1879, S&C has more than 1,000 lawyers located in offices in New York, Washington, D.C., Los Angeles, Palo Alto, London, Frankfurt, Paris, Brussels, Hong Kong, Beijing, Tokyo, Melbourne and Sydney.