Helen V. Cantwell is Co-Chair of the White Collar & Regulatory Defense Group and a litigation partner with extensive trial experience. Her practice focuses on white collar criminal defense, regulatory enforcement actions and internal investigations for a wide variety of corporations, financial institutions and non-profits. In addition to advising clients on their responses to state and federal investigations, she also advises these clients on their compliance obligations.

Ms. Cantwell also has deep experience in conducting sensitive investigations involving allegations of sexual misconduct and sexual harassment, dating back to her service as a prosecutor in the Manhattan DA’s Sex Crimes Unit.

Ms. Cantwell was named a Litigator of the Year by The American Lawyer for 2021, after being named Litigator of the Week by that publication in January for settling federal investigations into clients Toyota and Capital One on back-to-back days, without any criminal charges against either company. Chambers USA (2024) recognizes Ms. Cantwell as a top tier practitioner in white collar criminal defense and investigations matters. According to clients, “she not only has subject matter expertise but also very well-rounded judgment and she is able to see the bigger picture.” In previous editions of the guide, she is described as “superb” and “cool, calm, collected and strategic.” Sources have also said she is “a terrific lawyer,” “a force of nature,” “tenacious and smart” and “at the top of her game.” She is “smart, extremely confident,” and “her judgment is just impeccable and she has a mind like a steel trap.” She is described as “incredibly bright and sharp” by fellow practitioners, who praise her ability to “get up to speed lightning fast.” She receives further praise from clients who commend her “standout judgment and attention to detail.”

Prior to joining the firm, Ms. Cantwell served for eight years as an Assistant United States Attorney for the Southern District of New York. During her tenure in the U.S. Attorney’s Office, she was a member of the Securities and Commodities Fraud Task Force and worked closely with the Securities and Exchange Commission, the Commodities Futures Trading Commission and other law enforcement and regulatory agencies. Ms. Cantwell joined the U.S. Attorney’s Office in 2000, after four years as an Assistant District Attorney in the New York County District Attorney’s Office. She is a recipient of the Department of Justice Director’s Award for Superior Performance as a Federal Prosecutor.

After the Manhattan District Attorney’s Office, Ms. Cantwell spent a year working in Malaysia with the International Women’s Rights Action Watch, under a fellowship grant from the Henry Luce Foundation.

Ms. Cantwell joined Debevoise in 2008. She earned her J.D. cum laude in 1995 from Harvard Law School, where she was President of the Harvard Legal Aid Bureau, and her B.A. magna cum laude from Wellesley College in 1992.


  • Harvard Law School, 1995, J.D.
  • Wellesley College, 1992, B.A.

Bar Admissions

  • New York