These proceedings represent the work of contributors to the 15th International Conference on Cyber Warfare and Security (ICCWS 2020), hosted by Old Dominion University (ODU), Norfolk, Virginia on 12-13 March 2020. The Conference Chair is Prof. Brian K. Payne and the Programme Chair is Prof. Hongyi Wu, both from Old Dominion University. ICCWS is now a well-established event on the academic research calendar and now in its 15th 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. With an initial submission of 139 abstracts, after the double blind, peer review process there are 59 Academic research papers, 7 PhD research papers, 4 Masters Research papers, 1 non-academic paper and 1 work-in-progress paper published in these Conference Proceedings. These papers represent research from Australia, Canada, Czech Republic, Estonia, Finland, France, Germany, Ghana, Lesotho, Malaysia, Namibia, Nigeria, Norway, Portugal, South Africa, South Korea, Sweden, the Netherlands, and USA.