Felicia H. Ellsworth

Felicia Ellsworth is a first-chair trial lawyer and experienced appellate advocate who combines her significant trial experience with her recognized appellate skill to represent clients at all stages of litigation. Ms. Ellsworth’s practice focuses on high-stakes disputes in both state and federal trial and appellate courts, including the Supreme Court of the United States. She is a member of the American Law Institute, which is the leading independent organization in the United States producing scholarly work to improve the law, and is routinely recognized as a leading trial and appellate and litigator in industry publications, including Law360Massachusetts Lawyers Weekly and The American Lawyer, which named her “Litigator of the Week” in October 2019.

Most recently, Ms. Ellsworth was trial counsel to Harvard University in the case challenging its use of race in its undergraduate admissions practice, which earned her the "Litigator of the Week" title. She has also represented numerous clients in disputes on a wide range of legal issues with a particular emphasis on complex disputes involving technology-focused clients, including administrative law, bankruptcy, commercial law, constitutional law, federal criminal law, the First Amendment, Indian law, intellectual property, jurisdiction, preemption and real property. 

Ms. Ellsworth has authored several merits briefs and numerous certiorari-stage briefs in cases before the Supreme Court of the United States, and has also authored successful briefs and dispositive motions before federal and state courts of appeals, including  the Massachusetts Appeals Court and Supreme Judicial Court and the US Courts of Appeals for the First, Second, Fourth, Fifth, Sixth, Seventh, Ninth, Tenth and Federal Circuits. She has argued before both federal and state appeals courts, including the First, Second and Sixth Circuits, as well as the Massachusetts Appeals Court.

In 2019, Ms. Ellsworth was appointed by the Justices of the Supreme Judicial Court of Massachusetts to the Standing Committee on Pro Bono Legal Services for the Massachusetts Court System. She also serves by appointment on the court system's Standing Advisory Committee on the Rules of Civil and Appellate Procedure. Ms. Ellsworth also previously worked as a Special District Attorney in the Middlesex District Attorney's Office in 2010 and 2011, where she prosecuted cases involving violent crimes, financial fraud, and many other offenses.

As co-chair of the firm's Pro Bono and Community Service Committee, Ms. Ellsworth maintains a robust pro bono practice, including representing clients in constitutional cases, criminal appeals, immigration proceedings and civil rights actions. She played a lead role in WilmerHale’s representation as co-counsel with the Commonwealth of Massachusetts in the Commonwealth’s challenge to the constitutionality of DOMA, leading to the historic Supreme Court ruling favoring marriage equality. She has also been appointed to the First Circuit Court of Appeals Criminal Justice Act panel and is a member of the Board of Trustees of the Women’s Bar Foundation.

A native of Boston, Ms. Ellsworth served as a law clerk to Chief Justice John G. Roberts, Jr. of the Supreme Court of the United States and to Judge Michael Boudin of the US Court of Appeals for the First Circuit. She attended Georgetown University’s School of Foreign Service and the University of Chicago Law School, where she was the editor-in-chief of The University of Chicago Law Review.


  • Secured judgment on all counts for Harvard University in a case challenging its use of race in the undergraduate admissions process following three-week federal bench trial. 

  • Trial and appellate counsel to the Berkshire Museum in multiple successful appellate proceedings in relation to the Museum’s art collection, including two paintings by Norman Rockwell.

  • Trial and appellate counsel to the NCAA in an eight-day jury trial for defamation that resulted in a unanimous jury verdict for the NCAA after only a few hours of deliberations.

  • Trial and appellate counsel to the State of Vermont in various matters relating to the proposed relicensing, decommissioning and sale of the Vermont Yankee Nuclear Power Station in proceedings before the Vermont Public Utility Commission.

  • Trial and appellate counsel in an ongoing case involving an important question of federal preemption and Indian law under the Indian Gaming Regulatory Act involving a proposed tribal casino on the island of Martha’s Vineyard.

  • Trial counsel to a major entertainment company in putative class action lawsuits in federal and state court arising out of a highly publicized data breach.

  • Appellate counsel to a multinational networking equipment manufacturer in a successful patent infringement appeal in the Federal Circuit and Supreme Court. 

  • Appellate counsel to a private beverage company in the Ninth Circuit and Supreme Court in a successful challenge to a competitor’s misleading labeling, resulting in a unanimous ruling in the client's favor in a case that attracted significant press coverage, including in The New York Times and Law360.

  • Appellate counsel to a medical device manufacturer in a successful trade secrets appeal to the Supreme Judicial Court of Massachusetts.

  • Appellate counsel to a major medical device manufacturer in a successful appeal to the Federal Circuit, reversing a multi–million dollar attorneys fees award.

  • Appellate counsel to Honda in a successful appeal to the Second Circuit.


  • Award Text

    Named Litigator
    of the Week

    The American Lawyer


  • Award Text

    Named to the Top Women of Law List

    Massachusetts Lawyers Weekly


  • Award Text

    Selected as a Massachusetts Super Lawyer for Appellate

    Super Lawyers


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  • Education

    • JD, University of Chicago Law School, 2005

      High Honors Order of the Coif; Editor-in-Chief, The University of Chicago Law Review
    • BS, Foreign Service, Georgetown University, School of Foreign Service, 2000

      cum laude Honors Certificate in Muslim-Christian Understanding
  • Admissions

    • Massachusetts

  • Clerkships

    • The Hon. Michael Boudin, US Court of Appeals for the First Circuit, 2005 - 2006

    • The Hon. John G. Roberts, Jr., US Supreme Court, 2006 - 2007