Stephen Donald serves as the Technical Executive Director for MANTECH’s Cyber Practice, bringing more than 25 years of distinguished leadership at the intersection of national defense, advanced technology, and cyber operations. A seasoned Flag Officer in the U.S. Navy Reserve and a proven executive in both government and industry, Stephen is widely recognized for driving innovation in large-scale cyber modernization, multi-domain operations, and mission-critical security transformation across the Department of Defense, Intelligence Community, and commercial sector.

Throughout his military career, Stephen has led some of the nation’s most consequential cyber organizations and missions. His leadership roles have included key positions at U.S Cyber Command, U.S. Fleet Cyber Command, Joint Task Force ARES, and multiple major cyber and intelligence commands responsible for defending global networks, integrating offensive and defensive cyber operations, and advancing readiness across joint forces. His portfolio included stewardship of modernization efforts that strengthened operational resilience and improved mission outcomes across millions of endpoints and users.

In parallel with his service, Stephen has built a distinguished career in the commercial cybersecurity arena. He has founded and successfully scaled multiple cybersecurity companies, delivering advanced capabilities in threat detection, analytics, network defense, and cyber operations support. His entrepreneurial ventures have contributed to breakthrough technologies and business outcomes, and his commercial leadership experience enables him to bridge cutting-edge innovation with mission-driven requirements in national security environments.

Stephen has advised senior leaders across the DoD and IC on cyber readiness, risk management, supply chain security, and digital modernization strategies, and has played a central role in shaping next-generation approaches to secure, scalable cyber ecosystems.

At MANTECH, Stephen leads the technical strategy, innovation direction, and capability development for the Cyber Practice. His focus includes strengthening MANTECH’s cyber portfolio, enhancing cross-mission interoperability, expanding innovation pathways with industry and academia, and ensuring that the company’s cyber capabilities remain positioned for the future.

He holds advanced expertise in cybersecurity policy, emerging technology, cyber operations, and national security strategy, and is a frequent advisor and collaborator across government, academia, and industry. Stephen continues to serve as a trusted leader committed to strengthening the nation’s cyber posture and guiding the next generation of cyber professionals.