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Clifford Chance

Clifford Chance
Leigh Oliver (She/Her)

Leigh Oliver (She/Her)


Leigh Oliver (She/Her)

Leigh Oliver specializes in antitrust issues ranging from bet-the-company merger control matters to state and federal antitrust investigations. She has two decades of experience advising clients in heavily scrutinized industries, including healthcare, life sciences, aerospace and defense and industrials. She regularly represents clients before federal and state antitrust agencies and in merger litigation in federal court.

  • Mondelēz International in the sale of its gum business to Perfetti Van Melle
  • UnitedHealth Group and its subsidiary Optum on various matters, including the successful defense of its acquisition of Change Healthcare which was challenged by U.S. Department of Justice Antitrust Division
  • Laboratory Corporation of America with respect to numerous transactions
  • Alcon in various transactions
  • Einstein Health Network in its 2020 merger with Thomas Jefferson University
  • Beaumont Health in its merger with Spectrum Health
  • Aspirus Inc. in its acquisition of Ascension hospitals in Wisconsin
  • Penn State Health in its acquisition of Geinsinger’s Holy Spirit Hospital
  • Atrium and Wake Forest Baptist Medical Center in their combination
  • UW Health and UnityPoint in their combination of provider and plan businesses
  • PPG, Inc. in various transactions and matters
  • Gencorp-Aerojet in its acquisition of Pratt & Whitney Rocketdyne
  • Orbital Sciences in its acquisition of ATK

News and client work

View all news and client work featuring Leigh Oliver

Contact details

Career and qualifications

  • Haverford College (BA Political Science) 2000
  • The Catholic University of America, Columbus School of Law (JD) 2004
  • Admitted as Attorney-at-Law in the District of Columbia 2004
  • Joined Clifford Chance as a Partner 2022

Professional bodies

  • Co-Chair of the ABA Antitrust Section's Committee Operations, American Bar Association
  • Member of the American Health Lawyers Association (AHLA)
  • adjunct professor at The George Washington University Law School

Awards and citations

  • Recommended for Competition: Global Leaders
    Who's Who Legal, 2023
  • "Leigh Oliver is particularly commended for her work in healthcare-related antitrust matters. She regularly appears before the FTC in merger investigations and challenges."
    Band 5, Chambers USA: Antitrust, 2021-2023
  • Ranked as a Washington D.C. Super Lawyer, 2023
  • Ranked as a Leading Litigator in America
    Lawdragon 500 2023: Antitrust Clearance & Litigation
  • Leigh Oliver is particularly commended for her work in healthcare-related antitrust matters. She regularly appears before the FTC in merger investigations and challenges. Sources say, "She is extraordinarily attentive to detail and to strategy, an excellent team leader and very responsive to client needs."
    Chambers USA 2021: Antitrust (District of Columbia)
  • Ranked as Next Generation Partner
    Legal 500 USA 2019-2023, Healthcare: Advice to Service Providers
  • Competition: Future Leaders, Most Highly Regarded, Who's Who Legal, 2017-2021
  • 40 in their 40s: Notable Women Competition Professionals in Americas, W@, 2019
  • Lawyer of the Year - Under 40, Global Competition Review (GCR), 2017
  • Competition, Who's Who Legal, 2017
  • Mergers and Acquisitions Trailblazer, National Law Journal, 2016