At the recommendation of Arimura Shunsai, he became a tea-serving Buddhist monk for the daimyō of Satsuma, Shimazu Nariakira.

In 1869, two years after the establishment of the Meiji government, Saigō went to Europe with General Yamagata Aritomo to study European military organizations, tactics and technologies.

[2] In 1873, his brother Saigō Takamori resigned from the government, over the rejection of his proposal to invade Korea during the Seikanron debate.

[1] Saigō held a string of important positions in the Itō Hirobumi cabinet, including Navy Minister (1885, 1892–1902).

[2] As Minister of Internal Affairs, Saigō pushed strongly for the death penalty for Tsuda Sanzō, the accused in the Ōtsu incident of 1891, and threatened Kojima Korekata should the sentence be more lenient.

[2] In 1894, Saigō was given the rank of admiral, in recognition of his role as Navy minister, and his peerage title was elevated to that of marquis.

Saigō’s former residence (once in Meguro, Tokyo) is registered as an Important Cultural Property by the Japanese government and is now at the Meiji-mura historical park outside of Inuyama, Aichi Prefecture.