Koji Tachibana (born 1979) is a Japanese philosopher and ethicist specializing in virtue ethics, space ethics, and applied ethics. An Associate Professor at Chiba University, he explores the ethical challenges posed by emerging technologies, including space exploration, artificial intelligence, and neuroscience. His best-known book, "Uchū Kaihatsu no Tetsugaku: Kagaku de wa Wakaranai Saigo no Toi" ("The Philosophy of Space Exploration: The Final Questions Science Cannot Answer"), examines space exploration through the lenses of ethics and political philosophy, asking why humanity should explore space and what values should guide life beyond Earth.