David E. Dahlquist

David Dahlquist is a partner in Winston & Strawn’s Chicago office focusing on complex commercial litigation, with an emphasis on antitrust, healthcare, intellectual property, and class actions.


Mr. Dahlquist is a member of the Trial Bar in the Northern District of Illinois and has significant trial experience, including first chair and supporting roles, in jury trials and bench trials in multiple jurisdictions across the United States.

Mr. Dahlquist lead the effort to obtain complete dismissal of federal antitrust claims on behalf of NorthShore University HealthSystem (Frantzides, et al. v. NorthShore, et al., 787 F. Supp. 2d 725 (N.D. Ill. 2011)) as well as dismissal of Medicare Fraud qui tam claims on behalf of NorthShore University HealthSystem. (U.S. ex rel Walner v. NorthShore, 660 F. Supp. 2d 891 (N.D. Ill. 2009)).

Mr. Dahlquist was also part of the trial team for the first two consummated merger cases tried before the Federal Trade Commission in more than two decades. (In re Chicago Bridge and Iron(2005) and In re Evanston Northwestern Healthcare (2007)). He was a key participant in the trial and appeal to the FTC that reversed a divestiture order in the Evanston Northwestern Healthcare matter.

Mr. Dahlquist also has significant intellectual property experience including multiple patent trials. He was part of the trial team that successfully obtained a multi-million dollar jury verdict on behalf of Verizon related to voice-over-Internet protocol patents against Vonage. (Verizon Communications v. Vonage Holdings, 503 F.3d 1295 (Fed. Cir. 2007)).

Mr. Dahlquist has also done significant work on behalf of clients in class actions, civil and criminal price-fixing investigations, white collar criminal defense, healthcare acquisitions, clinical integration, Medicare fraud investigations, environmental litigation, and various competition issues.

Mr. Dahlquist received a B.A. in Political Science from the University of Illinois at Urbana-Champaign in 1998 and a J.D., with honors, from DePaul University College of Law in 2001, where he was elected to the Order of the Coif and served as editor-in-chief of the DePaul Law Review.

Honors & Awards

Chicago Magazine and Super Lawyers have consistently named Mr. Dahlquist as a Rising Star from 2008-2013 with specific recognition for antitrust litigation. In 2014, Winston & Strawn was named the Chicago Litigation Department of the Yearfor white-collar defense by The National Law Journal.


Mr. Dahlquist is an active member of the American Bar Association Antitrust Section and Health Law Section. Mr. Dahlquist also serves on the Advisory Board for the DePaul University Center for Intellectual Property Law and Information Technology. Mr. Dahlquist is a frequent guest lecturer on antitrust matters at DePaul University and also regularly participates in pro bono representation and educational activities.

Mr. Dahlquist is a member of the Constitutional Rights Foundation Chicago and an active participant in the Lawyers in the Classroom project which places attorney volunteers in classrooms at Chicago Public Schools to lead interactive lessons on the United States Constitution.