The Imperial Japanese Army Nakano School (陸軍中野学校, Rikugun Nakano Gakkō) was the primary training center for military intelligence operations by the Imperial Japanese Army during World War II.

The Imperial Japanese Army had always placed a high priority on the use of unconventional military tactics. Before the time of the First Sino-Japanese War, Japanese operatives, posing as businessmen, and Buddhist missionaries in China, Manchuria and Russia established detailed intelligence networks for the production of maps, recruiting local support, and gathering information on opposing forces. Japanese spies would often seek to be recruited as personal servants to foreign officers or as ordinary laborers for construction projects on foreign military works. Such activities fell under the oversight of the 2nd Section of the Imperial Japanese Army General Staff Office.

In July 1938, after a number of attempts to penetrate the military of the Soviet Union had failed, and efforts to recruit White Russians had failed, Army leadership felt that a more "systematic" approach to the training of intelligence operatives was required. Lt. Col. Shun Akigusa (秋草 俊) was instructed to organize the curriculum of a special training school, to be located in 4 Chome Nakano of Nakano, Tokyo. The sign on the school read "Army Correspondence Research Center" to make the public believe that the school was focused on correspondence and not top secret training

The Nakano School was initially focused on Russia, teaching primarily Russian as a foreign language. In 1940, administration of the school was handed over to Lt. Col. Masao Ueda (上田昌雄), who in 1938 had provided considerable intelligence on Russia from his post as military attaché (a common position for Nakano graduates) in Poland.

After the attack on Pearl Harbor, and the start of World War II, the Nakano School changed its focus to southern targets. After the firebombing of Tokyo, it was relocated to Tomioka-machi, Gunma prefecture.

A small school, over its history, the Nakano School had over 2500 graduates, who were trained in a variety of subject matters related to counterintelligence, military intelligence, covert operations, sabotage, foreign languages, and aikido, along with unconventional military techniques in general such as guerrilla warfare. Extended courses were provided on a wide variety of topics including philosophy, history, current events, martial arts, propaganda, and various facets of covert action.

While small, its graduates occasionally had dramatic successes, such as the intact capture of oil facilities in Palembang, Netherlands East Indies, by Nakano School-trained paratroopers. Nakano graduates were also very active in Burma, India, and Okinawa campaigns.

F Kikan, I Kikan and Minami Kikan (ja) were heavily staffed with Nakano graduates. F Kikan and I Kikan were directed against British India, and were instrumental in forming the Indian National Army and supporting the Azad Hind movement in Japanese-occupied Malaya and Singapore. It also worked with Indonesian nationalists seeking the independence of the Netherlands East Indies. Its efforts to promote anti-British and anti-Dutch movements lasted past the end of the war, and played a role in the independence of India and Indonesia.