Ian M. Dumain

Ian M. Dumain is a Partner and the Firm’s General Counsel.

Ian represents businesses and individuals in their most important matters and helps them resolve their knottiest problems.

Ian has represented financial services firms, pharmaceutical and medical device companies, ratings agencies, the national governing body of a sport, law firms, an accounting firm, corporate executives, insurance companies, hedge funds, media companies, world-renowned artists, and prisoners. He has handled cases under the federal securities laws; state contract, fiduciary, privacy, and tort law; state and federal false claims laws; Food and Drug Administration regulations; the federal Visual Artists’ Rights Act; the federal Trust Indenture Act; the federal civil rights laws; and state post-conviction laws, among other laws and regulations.

Recently, after less than a year on the case, Ian brought a favorable end to a decades-long dispute between two money managers and two of their former clients, which had been litigated in federal trial and appellate courts, bankruptcy courts, and state court in three states. Before that, Ian represented the former CEO of the Ashley Madison website in class action data-breach litigation brought by the website’s former customers and in an indemnification dispute with the company that owned the website; both disputes were resolved favorably. 

Ian has extensive trial and arbitration experience. Ian has cross-examined senior executives of Fortune 500 companies, investment bankers, accountants, tax lawyers, economics professors, thoroughbred horsemen, a DNA scientist, a francophone professor of African law, and others. 

At his previous firm, he was one of four lawyers who defended Guidant Corporation at trial against claims that Guidant breached a $21.5 billion merger agreement and settled the case after trial for a small fraction of the claimed damages. He also led a trial team in a dispute between an internationally renowned artist and an airport terminal over the removal of the artist’s sculpture from the terminal. The case settled on favorable terms after Ian’s opening statement, and the sculpture hangs in the terminal to this day.At his first trial as a lawyer, Ian obtained the then-largest punitive damages award against an individual in Nevada history.

Ian also has a winning appellate track record. He has obtained affirmances and reversals, in federal court and state court. His recent appellate experience includes briefing or arguing winning appeals in the California Court of Appeals (concerning the intersection of a contractual forum-selection clause and the California Invasion of Privacy Act), the New York Appellate Division (concerning the appealability of a sanctions order), the United States Court of Appeals for the Second Circuit (concerning a motion to compel arbitration), and the United States Court of Appeals for the Fourth Circuit (concerning claims for defamation and other intentional torts arising from a disciplinary proceeding).

Ian knows, however, that often the best outcome is avoiding the courtroom. His clear-eyed litigation assessments, candid advice, and skillful negotiation produce favorable settlements before litigation has begun.

Outside the office, Ian is an active member of his local community. He is a trustee and the Governance Vice President of The Leffell School, a trustee and vice president of Camp Ramah in the Berkshires, and a former trustee and vice president of Temple Israel Center (White Plains, NY).

The matters discussed above include representations at previous employers.


Benjamin N. Cardozo School of Law, J.D. summa cum laude

Cardozo Law Review, Executive Editor

Felix Frankfurter Award, for combined outstanding academic achievement, maturity, responsibility, diligence, and judgment

Benjamin N. Cardozo Writing Award, for best course or independent research paper

Hamilton College, B.A.


  • New York
  • United States District Court for the District of Connecticut
  • United States District Court for the Eastern District of New York
  • United States District Court for the Southern District of New York
  • United States District Court for the Northern District of New York
  • United States Court of Appeals for the Second Circuit
  • United States Court of Appeals for the Fourth Circuit
  • United States Court of Appeals for the Ninth Circuit


  • Boies Schiller Flexner, Partner
  • Patterson Belknap Webb & Tyler, Associate
  • Innocence Project, Clinic Intern and Research Assistant to Professor Barry Scheck


  • Innocence Project, Advocate for Justice
  • Law360, Rising Star (Healthcare)
  • Superlawyers, Superlawyer & Rising Star
  • New York City Bar Association, Thurgood Marshall Award
  • Westchester Jewish Council’s Honorable Samuel G. Fredman Leadership Development Institute


Preparing Your Witness to Testify at a Virtual Trial, Litigation (ABA Section of Litigation), June 9, 2020.

No Secret, No Defense, U.S. v. Progressive, 26 Cardozo Law Review 1323 (2005), republished in First Amendment Law Handbook, 2005-06 Edition (R. Smolla ed., 2006)