Mary Beth Maloney

Mary Beth Maloney is a first-chair trial lawyer for public companies, their boards, and senior executives in their highest-stakes federal and state court litigation, securities matters, government enforcement actions, and complex commercial disputes, with a particular focus on healthcare, life sciences, and financial services. She is regularly retained as lead trial counsel when public companies face existential threats—from regulators and watchdog organizations, in securities class actions and SEC enforcement matters, and in bet-the-company commercial disputes.

This year The American Lawyer’s Litigation Daily recognized Mary Beth’s performance on behalf of her clients twice. In March, she was named “Litigator of the Week” for her successful representation of five Tenet Healthcare community hospitals following a five-day federal bench trial that resulted in a landmark decision under Florida law. In July, she was recognized for obtaining dismissal of a $700 million derivative action on behalf of Alcon in the Delaware Court of Chancery, where she argued the successful motion to dismiss. Chambers USA calls her a “tenacious litigator” who fights for “the best outcome from every angle possible.” She is ranked by Chambers USA in New York Securities Litigation, among other recognitions.

Recent Trial Wins

In January 2026, Mary Beth served as lead trial counsel for five Tenet Healthcare community hospitals in a federal bench trial against The Leapfrog Group in the Southern District of Florida. She secured a sweeping post-trial decision holding that Leapfrog's hospital safety-grading methodology constituted an unfair and deceptive business practice under Florida law and granting the hospitals complete injunctive relief. She continues to represent the hospitals in post-judgment proceedings.

Mary Beth represents Alcon in the Delaware Court of Chancery. In June 2026, she argued the motion to dismiss a $700 million derivative action before Chancellor Kathaleen McCormick and secured complete dismissal with prejudice of all six counts. Mary Beth also co-first-chaired the January 2025 trial in Alcon v. Aurion Biotech, involving a corporate-governance and voting-rights dispute, before Chancellor McCormick. She continues to represent Alcon in related matters.

Complex Commercial Litigation

Mary Beth serves as lead litigation counsel for Tenet Healthcare across an active portfolio of commercial matters, including pending litigation against Eisenhower Medical Center in California state court. She also advises Citadel Americas, one of the world's largest hedge funds, in employment-mobility disputes.

Her other recent lead-counsel representations include:

• Xerox in a pre-litigation commercial dispute, securing more than $200 million in relief.
• Coupang, the "Amazon of South Korea," in a contract dispute resolved in the Delaware Court of Chancery.
• An international hedge fund in a dispute with the Federal Deposit Insurance Corporation before the U.S. District Court of the District of Columbia arising from the collapse of Silicon Valley Bank.
• A group of investment funds in a contract dispute in the Southern District of New York and the Delaware Bankruptcy Court, resulting in complete dismissal.
• Patriarch Partners Management Services in a contract dispute for management fees in New York Supreme Court.

Earlier in her career, Mary Beth was part of the Gibson Dunn team that represented Chevron Corporation in its successful RICO and fraud action barring enforcement of a $9 billion Ecuadorian judgment.

Life Science Representations

Mary Beth represents leading life sciences companies—including Amgen, Esperion Therapeutics, Gilead Sciences, Immedica, Novartis, and US WorldMeds—in royalty, licensing, collaboration, milestone-payment, and commercialization disputes. In 2026, on behalf of US WorldMeds, she obtained a complete summary judgment win, including an award of attorneys' fees, in a milestone dispute in Delaware Superior Court.

Other recent representations include:

• Novartis in numerous matters at both the pre-litigation stage and in active litigation.
• Gilead in a confidential commercial dispute.
• Esperion Therapeutics in a $300 million pharmaceutical licensing dispute in the Southern District of New York, resolved through settlement.

Securities Litigation

Mary Beth's securities practice covers civil class actions, derivative suits, and SEC investigations and enforcement actions for public companies, financial institutions, and senior executives. Representations include:

• Goldman Sachs, as underwriter counsel, in securities litigation in the Southern District of New York, dismissed in 2026.
• Hut 8, a FinTech company, in a securities-fraud class action in the Southern District of New York, resolved by settlement, and numerous follow-on actions.
• Estée Lauder in a securities fraud class action in the Southern District of New York, resolved by settlement.
• Centerview Partners and one of its managing directors, securing complete dismissal of securities and common-law fraud claims, affirmed by the Fifth Circuit.
• Sequential Brands Group, Inc. and its former directors, securing resolution without penalty of a multi-year SEC investigation and favorable resolution of the related civil securities-fraud class action in the Southern District of New York.
• Vale, Brazil's largest mining company, in a securities-fraud class action in the Southern District of New York, resolved favorably by settlement.
• Immunomedics, a Gilead company, and its former executives in a securities-fraud class action in the District of New Jersey, resolved favorably.

She also represented Lynn Tilton and Patriarch Partners against SEC fraud charges, defeating debarment and $200 million in requested disgorgement.

Thought Leadership and Speaking

Mary Beth co-authored “Tariffs and Royalties in License Agreements: Key Considerations for Life Sciences” (April 2025). She regularly speaks on license agreement disputes, including at the Consero Legal Leaders in Life Sciences Forum and has appeared at the J.P. Morgan Healthcare Conference and the TD Cowen Investor Conference on behalf of her life sciences clients.

Boards and Affiliations

Mary Beth serves on the New York State Permanent Commission on Access to Justice, the Board of Directors of the Center for Justice Innovation, and the Board of Directors of the New York City Urban Debate League. She is also an Advisory Board Member for Women in Funds.

Prior Experience

Before joining Gibson Dunn, Mary Beth clerked for the Honorable Alicemarie H. Stotler, then Chief Judge of the United States District Court for the Central District of California. She previously spent six years working in the California State Legislature.

Education

• J.D., University of Southern California Gould School of Law (Editor-in-Chief, Southern California Interdisciplinary Law Journal)
• B.A., Barnard College (Phi Beta Kappa; Erica Jong Writing Fellow)