
William Sinclair
PartnerDownload VCard
Office: 410.385.2225
Direct: 410.385.9116
Fax: 410.547.2432
Bill Sinclair is the partner-in-charge of the firm’s Business Litigation Group. His practice covers white-collar criminal defense and complex civil litigation. He also handles select personal injury and transactional matters.
J.D., University of Virginia School of Law, 2002
B.A., University of California at San Diego, 1999
Magna Cum Laude
California
Georgia
Maryland
All California District Courts
U.S. Court of Appeals for the Fourth, Ninth and Eleventh Circuits
U.S. District Court for the District of Columbia
U.S. District Court for the Northern District of Georgia
U.S. District Court for the District of Maryland
United States Supreme Court
Bill has tried jury and non-jury civil matters as both plaintiff's and defense counsel, as well as criminal matters, in state and federal courts in the District of Columbia and Maryland. He has also argued before the United States Courts of Appeals for the Fourth and Ninth Circuits and the Maryland Court of Special Appeals and state and federal trial courts in California, Minnesota, Georgia, Virginia, the District of Columbia, Maryland and New Jersey.
Bill’s clients have included corporations, individuals, and public agencies and utilities in toxic tort, environmental, and product liability cases; personal injury matters; civil rights cases; commercial and employment matters; land use, construction and other real estate disputes; and environmental, health care, and securities enforcement proceedings and investigations as well as other complex crimes.
Class actions are a significant part of Bill’s practice. He was co-lead plaintiff’s counsel in a federal class action against a local municipality that resulted in monetary and injunctive relief for his clients; in a concussion matter against the National Hockey League that resulted in a meaningful settlement for his clients; and drug use litigation against the National Football League. He has also served as local counsel in numerous class action matters. On the other side of the coin, he has served as co-lead defense counsel in a state putative class action product liability suit against a local utility and a series of putative and certified class actions in Maryland involving purported RESPA kickbacks that resulted in significant defense wins. He also served as co-lead defense counsel in a state class action matter involving landlord-tenant matters that resulted in a favorable settlement for his client.
Reported decisions in which Bill argued or briefed the matter, or both, include:
• Dent v. National Football League, 968 F.3d 1126 (9th Cir. 2020);
• Dent v. National Football League, 902 F.3d 1109 (9th Cir. 2018);
• Nanni v. Aberdeen Marketplace, Inc., 878 F.3d 447 (4th Cir. 2017);
Bill has served as an adjunct professor at the University of Maryland School of Law since 2009.
Bill graduated from the University of Virginia School of Law, where he was a member of Omicron Delta Kappa, Editor-in-Chief of the Virginia Environmental Law Journal, and Head Commissioner of the North Grounds Softball League, and the University of California at San Diego, where he was Phi Beta Kappa and received Highest Honors in History. While in college, he was captain of the Men’s Division I Varsity Volleyball team and the recipient of several academic and athletic awards
- 2003-04 Law Clerk, Hon. C. Christopher Hagy, U.S. District Court for the Northern District of Georgia
Who Rules the Roost? CWA Liability After Md. Ruling, Product Liability Law360, Portfolio Media Group (September 2010)
Status Check: Assessing Interior’s Implementation of the Energy Policy Act of 2005, Sustainable Development Law & Policy, Vol. VII, Issue 3 (Spring 2007)
Future of the “Feeney Amendment” After High Court’s Sentencing Rulings, Legal Backgrounder, 2005
- Best Lawyers 2021
- Maryland Top 100, 2017 - 2018
- Maryland Super Lawyers, 2014 - 2021


Bar Association for Baltimore City
Baltimore County Bar Association
State Bar of California
The District of Columbia Bar
State Bar of Georgia
Maryland Bar Foundation
Maryland State Bar Association
• Former Chair, Membership Committee
• Member, Committee on Laws
• Former Fellow, Leadership Academy
One Love, Maryland Regional Council