This paper explores Japan’s maritime and Arctic policies. Japan’s interest in the polar regions emerged early due to its geographical characteristics and the impacts of climate change, expanding its scientific research activities in the Arctic and Antarctic regions. Over time, Japan has broadened its involvement in the economic, scientific, environmental, and security domains. As a non-Arctic state, Japan has expressed its intent to contribute to resolving Arctic issues and has sought to take a leading role in Arctic governance within the international community. In 2007, Japan enacted the Basic Act on Ocean Policy to promote comprehensive and strategic maritime policies. Japan announced its 4th Basic Ocean Plan in 2023, which plays a crucial role in the sustainable use and protection of marine resources, marine environmental protection, and maritime safety. This paper comprehensively analyses Japan’s Basic Ocean Plans and Arctic policy, exploring the relationship and evolution between maritime and Arctic policies and examining how these policy changes reflect Japan’s international maritime strategy. While previous studies have treated maritime and Arctic policies separately, this paper analyses the interrelationship between the two, investigating the evolution of Japan’s maritime policy up to the present and the development and characteristics of its Arctic policy.