Prince Naruhiko Higashikuni (東久邇 稔彦 Higashikuni Naruhiko, also Higashikuni no miya Naruhiko ō (東久邇宮 稔彦王)) (3 December 1887 – 26 January 1990) was the 43rd Prime Minister of Japan from 17 August 1945 to 9 October 1945, a period of 54 days. An uncle of Emperor Shōwa twice over, Prince Higashikuni was the only member of the Japanese imperial family to head a cabinet. He also had the shortest tenure of any Japanese prime minister.

Prince Naruhiko was born in Kyoto, the ninth son of Prince Kuni Asahiko (Kuni no miya Asahiko Shinnō) and the court lady Terao Utako. His father, Prince Asahiko (also known as Shōren no miya Sun'yu and Nagakawa no miya Asahiko), was a son of Prince Fushimi Kuniie (Fushimi no miya Kuniie Shinnō), the head of one of four cadet imperial families entitled to provide a successor to the throne. Prince Naruhiko was a half-brother of Prince Kuni Kuniyoshi, the father of the future Empress Kojun, the wife of Emperor Showa. His other half-brothers, Prince Asaka, Prince Nashimoto, and Prince Kaya , all formed new branches of the imperial family during the Meiji period.

Emperor Meiji granted Prince Naruhiko the title Higashikuni no miya (Prince Higashikuni) and permission to start a new branch of the imperial family on 3 November 1906. Prince Higashikuni married the ninth daughter of Emperor Meiji, Princess Toshiko (11 May 1896 – 5 March 1978), on 18 May 1915. The couple had four sons. Their eldest son, Prince Morihiro of Higashikuni (Mr. Higashikuni Morihiro from October 1947) (6 May 1916 – 1 February 1969), married Princess Shigeko (9 December 1925 – 23 June 1961), the eldest daughter of Emperor Shōwa and Empress Kojun.

Before his brief tenure as prime minister, Prince Higashikuni was a career army officer. After graduating from the Imperial Military Academy (1908) and the Army War College (1914), he studied at the Ecole Supérieure de Guerre in Paris from 1920 to 1922. Upon his return to Japan, he eventually rose to the rank of general, having successively served as commander of the Fifth Infantry Brigade (1930–34), the Fourth Army Division (1934–37), the Military Aviation Department (1937–38), and the Second Army in China (1938–39). A member of the Supreme War Council from 1939, the prince served as commander of the Home Defense Command from 1941 to 1944. He colluded with several aristocrats and fellow imperial family members to oust General Hideki Tojo as prime minister following the fall of Saipan in 1944. Higashikuni lost his princely title and membership in the imperial family as a result of the American occupation reform of the Japanese imperial household in October 1947. As a private citizen, he operated several unsuccessful retail enterprises and briefly served as the chief priest of a new religious order (that was subsequently banned by American occupation authorities). Higashikuni died at the age of 102. Higashikuni is mainly remembered as Japan's first postwar prime minister.