Jaclyn Phillips

Associate, Washington, DC



Jaclyn Phillips is a senior associate in the Global Antitrust/Competition practice. Jaclyn guides clients through all stages of high-risk litigation and is frequently a core member of teams defending large-scale class actions. Jaclyn also handles investigations and litigations brought by U.S. and international regulators, including advising a leading global technology company in litigation brought by regulators abroad.

In addition to her litigation and investigations work, Jaclyn has an active antitrust counseling practice, advising clients on novel competition issues that require executable business solutions. Clients in various industries, including pharmaceuticals, technology, airlines, and food and beverage, have turned to her for counseling on a range of competition issues.

Jaclyn is a well-known author on timely and developing antitrust issues, including on emerging issues in the technology sector.

The Legal 500 US "Recommended" Jaclyn for her work in Antitrust Civil Litigations/Class Actions: Defense (2023), noting her "intellectual curiosity, indefatigable work ethic and professionalism." She was shortlisted as a Rising Star in Litigation for Women in Business Law awards (2023).

Jaclyn is committed to pro bono matters, with a particular focus on immigration matters. She has successfully helped her clients obtain asylum in the United States.

She is a frequent host of the ABA Antitrust Law Section's podcast Our Curious Amalgam, where she leads discussions with accomplished guests. She serves as a Vice Chair of the Podcast Programming Administrative Committee.

Jaclyn graduated from Georgetown University Law Center cum laude in 2013, where she served as an Articles & Notes Editor on the American Criminal Law Review.

Bars and Courts
District of Columbia
New York
US Court of Appeals for the Fourth Circuit
US Court of Appeals for the District of Columbia Circuit
US District Court for the Southern District of New York
US District Court for the Eastern District of New York
Georgetown University Law Center
Binghamton University


Counsel for amici curiae International Center for Law and Economics and scholars of law and economics supporting Defendant-Appellee Facebook, Inc. (now, Meta) in State of New York v. Facebook, Inc., No. 21-7078 (D.C. Cir. Mar. 28, 2022). 

Represented Gilead in complex antitrust class actions pending in N.D. Cal. concerning numerous innovative HIV treatments and related joint venture agreements and patent settlements. 

Represented Pfizer in ground-breaking litigation challenging Johnson & Johnson's efforts to deter biosimilar competition in respect of its blockbuster biologic, Remicade.

Representation of an airline in a class action alleging violations of Section 1 of the Sherman Act and state law, resulting in a successful motion to dismiss in the District of Maryland.

Representation of Allergan/Warner Chilcott in a reversal of class certification by the First Circuit US Court of Appeals. The ruling bans the widespread use of aggregate proof and post-trial affidavits as a substitute for fact-finding by juries under the Seventh Amendment of the US Constitution and Rule 23.

Representation of Boehringer Ingelheim in an antitrust class action challenging a patent settlement.

Representation of Allergan/Warner Chilcott in a number of antitrust class actions involving challenges to new-product introductions, patent settlements, and license agreements.

Key member of trial team that represented Anthem, Inc. against claims brought by the US Department of Justice to block Anthem's US$54 billion acquisition of Cigna Corporation.

Following trial, an expedited appeal to the D.C. Circuit was filed. The D.C. Circuit granted expedition, reviewed the appeal, heard oral argument and ruled on the merits, all within the span of two and a half months. This was the first time the D.C. Circuit has ever granted and heard an expedited appeal of a merger matter in such a compressed time frame, paving the way for more merger review in this appellate court. After receiving a split in the D.C. Circuit and a highly favorable dissent, Anthem filed a petition for a writ of certiorari to the Supreme Court only one week later.

Key member of a number of appellate teams that represented clients in the First, Second, Third, and D.C. Circuits.

Speaking Engagements

Jaclyn is a frequent co-host of the ABA Antitrust Law Section's podcast, Our Curious Amalgam, which explores topics in antitrust, competition, consumer protection, data protection, and privacy law. Take a listen to Jaclyn's recent Our Curious Amalgam podcasts!

Awards and Recognition

Recommended for Antitrust Civil – Civil Litigation/Class Actions: Defense, Legal 500 US 2023

Shortlisted as a Rising Star in Litigation, 2023 Women in Business Law Americas Awards

Jaclyn Phillips was included in the 2023 edition of the Best Lawyers: Ones to Watch in America™ for her work in Commercial Litigation.

Vice Chair of the Podcast Programming Administrative Committee for the ABA Antitrust Law Section during the 2022-2023 and 2023-2024 ABA year

Young Lawyer Representative of the ABA Antitrust Law Section for the 2021-2022 ABA year

2018 White & Case Pro Bono award

Jaclyn Phillips was named a "Litigator of the Week" by Global Competition Review for securing reversal of class certification in the Asacol® product-hopping litigation.