Conor L. McMahon

Associate | MCLEAN, VA
(703) 749-1000

Conor McMahon is an associate in Watt Tieder’s McLean, Virginia office. He focuses his practice on government contracts, construction, and commercial litigation. Conor draws upon his extensive experience in an array of government matters and complex litigation to provide practical insights and results-oriented advocacy for his clients.

Prior to joining Watt Tieder, Conor served for ten years as a Judge Advocate in the United States Marine Corps, where he was counsel on multiple jury and bench trials before both military and civilian tribunals. During his military career, he served as a civil law attorney, prosecutor, supervisory prosecutor, and Special Assistant United States Attorney. In these roles, Conor successfully litigated numerous complex cases and consistently achieved favorable outcomes.

Additionally, Conor has served as an Associate Counsel at a federal government Office of Inspector General (OIG), where he provided independent legal and policy counsel to OIG leadership on all investigations, audits, and inspections. As Lead Counsel for OIG’s Investigations Division, Conor oversaw legal review and advised on all civil, criminal, and administrative investigations, including cases involving the False Claims Act, contract and procurement fraud, federal conflicts of interest statutes, and whistleblower reprisal.

Honors & Awards

  • National Intelligence Professional Award (NIPA), 2025

Areas of Practice

  • Government Contracts
  • Construction
  • Commercial Litigation

Education

  • The Judge Advocate General’s Legal Center and School, LL.M., 2018
  • Roger Williams School of Law, J.D., 2012
  • George Washington University, B.A., 2008

Bar Admissions

  • Massachusetts

Court Admissions

  • Supreme Court of the United States
  • United States Court of Appeals for the Armed Forces