The maritime industry faces many pressing challenges due to increasing environmental and safety concerns. In light of these challenges, autonomous ships can provide potential solutions to addressing smart shipping, fuel efficiency, and safety issues. The development of marine autonomy technology will significantly improve the situation and is expected to become a cost-efficient alternative to conventional ships. Currently, automated shipping technology is rapidly transitioning from theoretical to practical applications as the number and scope of autonomous ship prototypes increase around the globe. These prototypes are widely used in both navy and commercial applications, such as ocean observation, coast patrols, underwater monitoring, and underwater production system operation. This reprint is a printed edition of the Special Issue on "Maritime Autonomous Surface Ships" that was published in the Journal of Marine Science and Engineering. It contains an editorial and 10 peer-reviewed research papers in the field of maritime ships, and the following topics are included in this book: ship control methods, collision avoidance, ship detection methods, and manoeuvring models and digital twin (DT) technology. The main goal of this reprint is to address key challenges, thereby promoting research on marine autonomous ships.