The third International Conference on Maritime Autonomous Surface Ship (ICMASS 2020) is the international conference which presents cutting edge works on autonomous ships to both academic and industry researchers. ICMASS addresses current research and academic activities focused on the development of Maritime Autonomous Surface Ships (MASS) technliogy and knowledge from all around the world. This conference is arranged by Korea Autonomous and Unmanned Ship Forum (KAUS) as a part of the International Network for Autonomous Ship (INAS) co-operation. The conference will facilitate high-level interaction and information exchange among MASS researchers and industrial developers. It will provide an interactive forum for discussion on recent and ongoing developments, key issues and challenges, and practices related to innovative applications in MASS systems. Researchers and practitioners from all over the world, from academia, industry, and authorities are invited to present their perspectives. In addition to regular scientific and technical papers, industrial p ractice reports are welcome from practitioners.