Mathew Rosengart

Practice Areas

Litigation

Media & Entertainment Litigation

White Collar Defense & Investigations

Career

Mathew Rosengart, Co-Chair of the National Media & Entertainment Litigation Group and recognized as one of the nation’s preeminent litigators, has been described as a “heavyweight attorney” by Law360, a “powerhouse lawyer” and “legend” by ABC, a “heavy-hitting trial lawyer” by The Legal 500, and “Hollywood’s King of Litigators” by Variety. Described by his long-time client Sean Penn as a “tough as nails streetfighter with a big brain and bigger principles,” Mathew is a former federal prosecutor, previously serving as a Supervisory Assistant United States Attorney and Justice Department Trial Attorney. A Governor of the Beverly Hills Bar Association, Mathew has been recognized as a California Lawyer Attorney of the Year and one of the Top 100 lawyers in the State by the Daily Journal; a “Trailblazer” (twice) by The National Law Journal; Lawyer of the Year by Above the Law; Litigator of the Week by The American Lawyer; Lawyer of the Week by Original Jurisdiction; a Top 100 Lawyer and LA500 Visionary Leader by the Los Angeles Business Journal; a “Litigation Star” by Benchmark Litigation; and a Leader of Influence and Top Litigator & Trial Attorney by the LA Business Journal, which honors “masters of their craft” who “go to the proverbial mat to fight for their clients.” The issue recognized Mathew as “one of the most influential litigators” in Los Angeles and a “go to litigator for Hollywood’s elite and Corporate America” who is “one of the nation’s preeminent litigators.” He was named “Entertainment Litigator of the Year” at the 2025 and 2024 Benchmark Litigation US awards, recognizing “the country’s most distinguished litigators and their firms for their exemplary work.”

Forbes named Mathew to its inaugural list of America’s Top 200 Lawyers 2024, which according to the publication, recognizes the finest lawyers in the profession, the leaders in their fields, and the attorneys most respected by peers and clients. According to Forbes, the criteria for those selected included reputation, influence on the legal landscape, and legal advocacy, which were evaluated to select those whose “integrity,” “expertise, passion, and purpose set them apart” as “the best in the business.”

Mathew has also been named by Lawdragon as one of the “500 Leading Litigators in America,” listed in The Best Lawyers in America, been named a Law360 MVP, which recognizes “the elite slate of attorneys” who “have distinguished themselves from their peers by securing hard-earned successes in high-stakes litigation,” and been lauded as a “legal powerhouse,” “powerful litigator,” “legal warrior” who is “principled,” and “high-powered” lawyer by Yahoo News, Newsweek, The View, The New York Times, and The Guardian. He has also been recognized by NPR as a lawyer with “a lot of star power,” by Los Angeles Magazine as a “winner” with “a long history of getting results for his big name clients,” and by The Wall Street Journal, The Hollywood Reporter, and NBC’s Today as a “high profile litigator,” a “Hollywood Power Lawyer,” and a “celebrity power attorney.”

Former Supreme Court Justice David Souter, for whom Mathew clerked on the New Hampshire Supreme Court, praised Mathew’s “intelligence,” “instinct,” and “personal integrity,” and his former Justice Department supervisor and now United States District Judge Robert J. Conrad called Mathew “one of the sharpest lawyers I’ve ever met at the Department of Justice,” whose “judgment is impeccable.”

Among many other cases, Mathew won a defamation lawsuit for Sean Penn; a $6 million “cutting rights” case for Academy Award winner Kenneth Lonergan regarding his film “Margaret” starring Matt Damon; won a multi-year $20 million arbitration for his client Credit Suisse against billionaire Ronald Lauder and 11 other claimants; obtained the complete dismissal at trial of all claims against his client CORE brough by the NLRB; and obtained a $14 million trial verdict in a New York trial (on a counterclaim) after extensive bi-coastal litigation for his hedge fund client against a film production company. Mathew also recently served as lead counsel for Fortune 20 company Verizon in one of the largest False Claims Act cases in the country, involving more than $500 million in claims.

Mathew has delivered Boston College Law School’s Dean’s Distinguished Lecture, spoken at Harvard Law School, lectured at law schools including Cornell and Northwestern, and was a keynote speaker at the ABA's Forum on the Entertainment and Sports Industries. He is a recipient of Trinity College of Dublin’s Praeses Elit Award, the highest honor bestowed by its Law Society, Variety’s Power of Law Award for legal excellence and philanthropy, and the Beverly Hills Bar Association’s Excellence in Advocacy Award. Mathew also serves on the Board of EBRP, the charitable organization founded by Jill and Eddie Vedder whose goal is to fight and defeat EB, a potentially fatal disease often inflicting children.

Concentrations:

Litigation

Media and entertainment litigation

White collar criminal defense

Professional Memberships

Board of Governors, Beverly Hills Bar Association, 2020-Present

Keynote Speaker, American Bar Association, Forum on the Entertainment and Sports Industries

Dean’s Distinguished Lecture, Boston College Law School

Speaker, Harvard Law School, Harvard Ass’n for Law and Business

Adjunct Professor of Law, "Criminal Procedure: Grand Jury Law & Practice," Fordham Law School, 2004-2006

Faculty, United States Attorney General's National Advocacy Center, lecturing in Trial Practice, 2000

Dean's Advisory Council, Tulane University

Member, Association of Business Trial Lawyers Los Angeles

Personal

Education

J.D., cum laude, Boston College Law School

B.A., Tulane University