John Tamasitis represents clients in state and federal courts in a variety of complex commercial litigation matters, including products liability defense, business contract disputes, financial services litigation, local zoning and regulatory matters that involve state and federal constitutional claims, and environmental litigation. John has extensive experience guiding corporate clients in a variety of matters involving commercial contracts, construction defects, corporate bankruptcy and insolvency, and both state and federal constitutional matters. John also has regularly been involved in cases involving commercial real estate disputes and unfair trade practices claims.

John is also a part of Williams Mullen’s firearms practice, which represents members of the firearms industry, including manufacturers, retailers, and government contractors. The firm also assists businesses outside the firearms industry with matters such as the unique issues faced by lenders to firearms industry and employers who must implement policies regarding employees’ possession and use of firearms.

John is focused on assisting clients throughout the litigation process, from pre-litigation strategy and guidance through settlement negotiations, arbitration, trials and appeals to the South Carolina Supreme Court and the United States Court of Appeals for the Fourth Circuit.

Prior to practicing law, John served as a captain in the United States Air Force with the Office of Special Investigations. While deployed, John led counterintelligence and counterinsurgency teams in Afghanistan in 2008 and 2009 and was awarded the Bronze Star for his service in and around Bagram Airfield. Back in the United States, John operated as a counterintelligence agent and was the appointed branch chief for two Air Force bases in Northwest Florida until heading off to law school in late 2011. In that role, John led and directed a team responsible for counterintelligence/anti-terrorism investigations in the area. He also provided research and technology counterintelligence protection services with the FBI and other government agencies to the Air Force's Special Operations Headquarters and the Air Force Research Laboratory Munitions Directorate, which conducts research and development for the Air Force's air-launched munitions and explosives program.

John is an active participant in his community, serving on the Advisory Committee for First Tee of Columbia, SC and as a founding member and president of Midlands Junior Golf Foundation.

John received his law degree from the University of South Carolina School of Law, magna cum laude, where he was both a member of the Order of the Coif and the Order of the Wig and Robe. During law school, John served as the Fourth Circuit Editor of the South Carolina Law Review. John earned his Bachelor of Science degree from the U.S. Air Force Academy where he was the class president and a cadet squadron commander.