LAWYER PROFILE
Diane P Sullivan

Diane P Sullivan

Global 2026

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Ranked in 1 practice area

About

Provided by Weil, Gotshal & Manges LLP

Practice Areas

Diane Sullivan is a renowned trial attorney, specializing in “first-of-kind,” “bet-the-company,” or otherwise high-profile matters that have garnered extensive media coverage across a range of practice areas and industries. She is routinely retained as lead trial counsel in high-stakes litigations. Diane has successfully tried cases for Fortune 500 companies in complex commercial, mass tort, class action, antitrust, patent, and environmental litigations in jurisdictions around the U.S. She has represented some of the biggest, most recognizable companies across industries, including Johnson & Johnson, Altria, AstraZeneca, Baxter Healthcare Corporation, Campbell Soup Company, ESPN, ExxonMobil, Frontier Communications, General Electric, GlaxoSmithKline, Merck, Philip Morris USA, Procter & Gamble, Repsol, SAC Capital, Sanofi, Toyobo, and Walgreens.

Professional Memberships

New Jersey Bar; New York Bar; DC Bar; admitted to practice before several federal courts.

Personal

Fairfield University (BA, 1984); University of Pennsylvania Law School (JD, 1987).

Chambers Review

Provided by Chambers

Chambers Global Guide

Litigation: Trial Lawyers - USA

Star Individual
Star Individuals

Individual Editorial
Diane Sullivan is renowned for her trial work, with particular expertise defending large medical device and pharmaceutical companies in major product liability trials, including high-stakes mass torts. She is based in the New York office at Weil.

Strengths

Provided by Chambers

  • Diane is one of the best trial lawyers ever in the country.

    Litigation: Trial LawyersChambers Global Guide
  • She is a brilliant trial lawyer. If your company is in a tight spot, you go to her.

    Litigation: Trial LawyersChambers Global Guide
  • She is one of the best trial lawyers in the country.

    Litigation: Trial LawyersChambers Global Guide
  • Dianne Sullivan is a premier trial lawyer in the country.

    Litigation: Trial LawyersChambers Global Guide

Ranked Individuals at Weil, Gotshal & Manges LLP (52)

China

  • Profile image of Chris Welty
    Chris Welty

    Corporate/M&A: Hong Kong-based (International Firms)

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  • Profile image of Henry Ong
    Henry Ong

    Corporate/M&A: Hong Kong-based (International Firms)

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  • Profile image of Peng Yu
    Peng Yu

    Private Equity: Buyouts & Venture Capital Investment (International Firms)

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  • Profile image of Chris Welty
    Chris Welty

    Private Equity: Buyouts & Venture Capital Investment (International Firms)

    View profile

France

Germany

UK

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