Leslie E. John


Leslie E. John is the Practice Leader of Ballard Spahr's Antitrust and Competition Group and Co-Leader of its False Advertising Litigation Team. Leslie concentrates on antitrust and complex litigation, and she has represented clients—many of them in the pharmaceutical and health care industries—in federal and state courts and before the U.S. Department of Justice and Federal Trade Commission. She also advises on antitrust issues in mergers and acquisitions, including securing pre-merger clearance under the Hart-Scott-Rodino Act, and counsels clients on antitrust compliance and risk management.

Leslie is recognized for her antitrust acumen in Chambers USA and is among Benchmark Litigation’s Top 250 Women in Litigation nationwide. Chambers USA described her as “methodical, very strategic and highly intellectual. She also communicates very effectively.” Leslie has substantial class action experience and was named “Litigator of the Week” by Global Competition Review in July 2015 for securing the decertification of an indirect purchaser class in a pharmaceutical antitrust case. She was honored as a “Top Women in Law” by The Legal Intelligencer in 2016.


Representative Matters

  • Represented a plaintiff pharmaceutical manufacturer in a Lanham Act (unfair competition) claim defeating attempts to dismiss the claims and later securing a settlement for her client on favorable terms.
  • Scored a landmark victory when the court granted summary judgment in favor of a global pharmaceutical company, dismissing claims that the company and a co-defendant filed sham patent cases to extend the period of exclusivity for its antidepressant medication and entered into an alleged reverse payment settlement.
  • Represented a provider of pharmaceutical data and analytics in a monopolization case filed against the world’s largest pharmaceutical data and analytics company, alleging that the defendant engaged in an unlawful scheme to eliminate its only formidable competitor left standing, defeating the efforts of the alleged monopolist to prevent plaintiff from filing a comprehensive amended and supplemental complaint challenging an array of exclusionary conduct, and settling the case on favorable terms.

Professional Highlights

Professional Activities

Philadelphia Bar Foundation, President, 2019-present; Vice President, 2007-2018; Board of Trustees, 2010-present; Secretary, 2013-2016; Co-Chair, 50th Anniversary Gala

Philadelphia Diversity Law Group, Co-President, 2019-present; Vice President, 2016-2018; Board of Directors, 2011-present

Forum of Executive Women, 2017-present

WOMEN'S WAY (nation's oldest women's funding federation), General Counsel, 2007-present

Ballard Spahr's Diversity, Equity, and Inclusion Council, Member 

Recognition & Accomplishments

Philadelphia Business Journal, "Best of the Bar," 2021

The Legal 500 US, Antitrust - Civil litigation/class action - defense and plaintiff, 2019-2021

Chambers USA, antitrust law (Pennsylvania), 2014-2021

Benchmark Litigation, "Local Litigation Star," Commercial Litigation, Antitrust, Securities, 2011-2021; named one of the "Top 250 Women in Litigation," 2012-2017, 2019, 2021, 2022

Speaking Engagements


Co-author, "FTC's Hospital Merger Enforcement Hangs in the Balance," Law360, June 16, 2016 

Co-author, "2 Assumptions Shape 3rd Circ. Reverse Payment Case," Law360, November 20, 2014

Co-author, "'Reverse Payment' Realities: Challenging Pervasive Assumptions Underlying Calls for Broad Antitrust Scrutiny of Patent Infringement Settlements," Bloomberg BNA Antitrust & Trade Regulation Report, November 14, 2014



University of California, Berkeley, School of Law (J.D. 1987)
Associate Editor, California Law Review
Member, Moot Court Board

University of California, Berkeley (A.B., summa cum laude, 1984)




U.S. Supreme Court