Skip to content Justin M. Holmes


Three Logan Square
1717 Arch Street
Suite 610
Philadelphia, PA 19103


J.D., Wake Forest School of Law, 2008

  • Order of the Barristers

B.A., Medieval Studies and Political Science, Pennsylvania State University, 2005


Super Lawyers “Rising Star: General Litigation” (2013-2014, 2016-2018)


Justin Holmes is Of Counsel practicing in the GRSM Philadelphia office. He has a national practice centered on defending organizations in class actions and other data privacy-related litigation, as well as handling regulatory investigations for clients from a wide breadth of industries in matters stemming from data privacy and security incidents. An experienced litigator, Justin has represented clients in federal district court, state court, and governmental tribunals throughout the country. He is well-versed in every stage of the litigation process.

Prior to joining GRSM, Justin practiced at a boutique national cyber-security law firm in Pennsylvania and also in Washington, D.C. at two international law firms representing corporate clients in complex commercial actions nationwide, with a focus on class action litigation and regulatory and governmental investigations. He further honed his first-chair trial skills by serving as an Assistant District Attorney in the Philadelphia District Attorney’s Office’s Homicide and Major Trials Units where he took over 50 serious felony cases to trial. 

While completing his J.D. at Wake Forest University School of Law, Justin was Captain of the National Trial Team and was also elected to the Order of the Barristers.

In addition to his corporate civil practice, he has dedicated a great deal of time to pro bono work representing clients seeking asylum based on persecution in their home country including first-chairing a case before the Arlington Immigration Court to obtain asylum for an Afghan family of six. Justin also works with the National Institute of Trial Advocacy (“NITA”) as a trial advocacy instructor, and in that capacity has worked with NITA to train and lead other lawyers and law students in discussions concerning trial technique topics including expert witnesses, evidence, direct and cross examination and opening and closing statements.

Outside of the office, Justin is President of the Board of Directors for the Harrisburg Area Confirmation Camp and is also a Board member of a central Pennsylvania service organization – LutheranHands.


  • Pennsylvania
  • Virginia
  • U.S. District Court for the District of Columbia
  • U.S. District Court for the Eastern District of Pennsylvania


Publications & Presentations