These proceedings represent the work of contributors to the 20th International Conference on Cyber Warfare and Security (ICCWS 2025), hosted by the William & Mary Law School, Williamsburg, Virginia, USA and sponsored by the William & Mary Center for Legal and Court Technology as well as Old Dominion University on 28-29 March 2025. The Conference Chair is Dr. Stephanie J. Blackmon, Williamsburg, Virginia, USA, and the Program Chair is Dr. Saltuk Karahan, from Old Dominion University, Norfolk, Virginia, USA.ICCWS is a well-established event on the academic research calendar and now in its 20th year, the key aim remains the opportunity for participants to share ideas and meet the people who hold them. The scope of papers will ensure an interesting two days. The subjects covered illustrate the wide range of topics that fall into this important and ever-growing area of research.The opening keynote presentation is given by Jeffrey Reynolds, Political-Military Advisor on the topic of Enabling a Multi-Domain NATO Alliance through Cyber and Space. The second day of the conference will open with an address by Francis A. "Skip" Hiser, III and his talk talk is titled: Challenges Today and Tomorrow: The Conundrum of Rapidly Evolving Threats, and Speed to Deploy/Execute Evolving Solutions in Cyber Security and Cyber Warfare.With an initial submission of 168 abstracts, after the double blind, peer review process there are 61 Academic research papers, 13 PhD research papers, 4 Masters Research papers, 1 Non-Academic Paper and 3 work-in-progress papers published in these Conference Proceedings. These papers represent research from Australia, Austria, Czech Republic, Finland, Germany, India, Japan, Kazakhstan, Kingdom of Saudi Arabia, Latvia, Netherlands, Nigeria, Norway, Qatar, South Africa, UK, United Arab Emirates, and the USA.
