Daniel J. Walker

  • Partner
  • Washington, DC
he/him/his
  • dwalker@hausfeld.com
  • +1 202-953-8212
Dan Walker

OVERVIEW

Dan is a partner in Hausfeld’s Washington, D.C. office, where he represents consumers, workers, and other plaintiffs in complex litigation against some of the largest companies in the world.

Dan has decades of experience litigating disputes involving contracts, patents, bankruptcy, and federal and state antitrust and consumer protection laws. These matters have spanned a wide range of industries, including health care, agriculture, pharmaceuticals, software, and financial services. In addition to his work obtaining monetary relief, he has been part of trial teams that have secured important structural and equitable relief on behalf of government and private plaintiffs, including in a landmark bankruptcy court trial seeking to recover for losses suffered in the wake of a sudden corporate collapse during the Great Recession.

Before joining Hausfeld, Dan practiced at another leading plaintiffs’ firm, where he helped recover hundreds of millions of dollars on behalf of plaintiffs, including in In re Broiler Chicken Grower Antitrust Litigation (settlements totaling $169 million on behalf of a class of chicken farmers), In re Loestrin 24 Fe Antitrust Litigation (settlements totaling $120 million for purchasers of hormonal birth control pills), In re Titanium Dioxide Antitrust Litigation (settlements totaling $163.5 million for purchasers of titanium dioxide), In re High Tech Employee Antitrust Litigation (settlements totaling $435 million for workers in the high‑tech industry), and Adriana Castro, M.D., P.A., et al. v. Sanofi Pasteur Inc. ($61.5 million settlement on behalf of pediatricians who purchased meningococcal vaccine).

While at the Federal Trade Commission, Dan investigated and litigated antitrust matters in the health care industry. In addition to leading nonpublic investigations in the pharmaceutical and health information technology sectors, he litigated Federal Trade Commission v. AbbVie Inc., et al., a case alleging that a brand‑name pharmaceutical manufacturer engaged in sham patent litigation to delay generic competition, and Federal Trade Commission v. Cephalon Inc., a “pay‑for‑delay” lawsuit over a brand manufacturer’s payments to four generic competitors in return for their agreement to delay entry. The Cephalon case settled shortly before trial for $1.2 billion—the largest equitable monetary relief ever secured by the Federal Trade Commission—as well as significant injunctive relief.

Dan speaks frequently on antitrust issues involving workers, health care, and intellectual property. Before entering private practice, he clerked for the Honorable Richard C. Wesley of the U.S. Court of Appeals for the Second Circuit.

Clients

Dan investigates and litigates complex cases on behalf of a wide range of plaintiffs, including municipalities, farmers, students, health care providers, and consumers of goods and services in a wide range of industries.

EDUCATION

Cornell University Law School, J.D., magna cum laude, Order of the Coif, 2005

Amherst College, B.A., magna cum laude, 1999

BAR ADMISSIONS

District of Columbia Bar

United States Supreme Court

United States District Court for the District of Columbia

United States District Court for the Eastern District of Pennsylvania

United States District Court for Eastern District of New York

United States District Court for the Southern District of New York

United States District Court for the Eastern District of Texas

United States Court of Appeals for the First Circuit

United States Court of Appeals for the Second Circuit

United States Court of Appeals for the Third Circuit

United States Court of Appeals for the Fourth Circuit

United States Court of Appeals for the Seventh Circuit

United States Court of Appeals for the Tenth Circuit

AFFILIATIONS

American Bar Association, Antitrust Law Section, Member

WHAT OTHERS SAY

American Antitrust Institute

  • Outstanding Antitrust Litigation Achievement in Private Law Practice Award for In re Broiler Chicken Grower Antitrust Litigation in 2023 and 2025

Chambers and Partners

  • Band 3, Antitrust: Mainly Plaintiff, District of Columbia, since 2025

Legal 500

  • Washington DC, Antitrust in 2026

Lawdragon

  • 500 Leading Global Antitrust & Competition Lawyers in 2026

Super Lawyers

  • Super Lawyer, Antitrust Litigation, Business Litigation, Washington, DC since 2020
  • Rising Stars, Washington, DC since 2013-2014