The New Japan–Republic of Korea Partnership towards the Twenty-first Century was a declaration made on October 8, 1998, between Japanese Prime Minister Keizō Obuchi and South Korean President Kim Dae-jung to reconfirm friendly relations between Japan and South Korea, as well as declare that both countries will discuss the future of Japan-South Korea relations in order to build a new Japan–South Korea partnership. This declaration is also called the Japan–South Korea Joint Declaration of 1998.

Japan–South Korea relations refers to the diplomatic relations between Japan and the Republic of Korea. As the Sea of Japan and the Korea Strait geographically separate the two nations, political interactions date back from the 6th century when the kingdom of Baekje officially established relations with Japan. During the ancient era, the southern region of the Korean Peninsula often served as the closest port for Japan to engage in economic trade and cultural exchange to and from mainland Asia. By 1910, Korea would become a colony of Japan until 1945.