Mary Marks Lathom is a strategic legal partner who bridges compliance and business needs. She fosters trust through collaboration and open dialogue and is also a certified mediator. Her philosophy is that as a lawyer she needs to collaborate with clients to turn legal challenges into opportunities for growth by working with them to design compliance controls that reduce risk and improve efficiency.

Mary works in high-stakes situations with and for her clients, and as a result is comfortable advising and collaborating to address a business’ most significant legal risks and tethering solutions to a client’s business objectives. Her experience includes federal government contracting, International Traffic in Arms Regulations (ITAR), export controls, internal investigations, CFIUS, the NISPOM, foreign ownership, control, and influence, as well as cybersecurity.

Mary brings creativity, clarity, and a passion for delivering actionable solutions. As a former executive and in-house counsel, Mary understands that legal advice must be practical, cost-conscious, and connected to business goals. 

Before joining Cassidy Law, Mary led enterprise-wide ethics, trade, and compliance programs at MasterBrand and Coherent Corp. She previously practiced international trade law at an AmLaw firm in Washington, D.C., and served as Assistant General Counsel and Attorney-Advisor at the FBI, advising on complex operational and compliance matters.

Mary’s creativity carries into her work as a thought leader who regularly shares her wisdom on effective compliance strategies and cybersecurity through presentations to the D.C Bar and the Public Contracting Institute. Mary loves the outdoors, hiking, painting, mixing perfumes and quality time with her husband, family, labradoodle and cats.

If your business works with the federal government, and you need legal counsel that aligns compliance strategy with real business objectives, at home and abroad, Mary Marks Lathom delivers practical, real-world solutions.