Marshal-General of the Navy (元帥海軍大将 gensui kaigun-taishō) (literally: Sea Force Marshal-General) was the highest rank in the prewar Imperial Japanese Navy. The term gensui was used for both the Navy and the Imperial Japanese Army, and was a largely honorific title awarded for extremely meritorious service to the Emperor. In the Meiji period, the title was awarded to 5 generals and 3 admirals. In the Taishō period it was awarded to 6 generals and 6 admirals, and in the Shōwa period it was awarded to 6 generals and 4 admirals. This rank is similar to fleet admiral.
Note that several were promoted the same year they died - these were posthumous promotions.
| Fleet Admiral | Name | (Birth-Death) | From | |
|---|---|---|---|---|
| 1 | 20 January 1898 | Marquis Saigo Tsugumichi | (1843-1902) | Kagoshima |
| 2 | 31 January 1906 | Count Itoh Sukeyuki | (1843-1914) | Kagoshima |
| 3 | 31 October 1911 | Viscount Inoue Yoshika | (1845-1929) | Kagoshima |
| 4 | 21 April 1913 | Marquis Togo Heihachiro | (1847-1934) | Kagoshima |
| 5 | 7 July 1913 | Prince Arisugawa Takehito | (1862-1913) | Imperial Family |
| 6 | 26 May 1917 | Baron Goro Ijuin | (1852-1921) | Kagoshima |
| 7 | 27 June 1922 | Prince Higashifushimi Yorihito | (1867-1922) | Imperial Family |
| 8 | 8 January 1923 | Baron Hayao Shimamura | (1858-1923) | Kochi |
| 9 | 24 August 1923 | Baron Tomozaburo Kato | (1861-1923) | Hiroshima |
| 10 | 27 May 1932 | Prince Fushimi Hiroyasu | (1876-1946) | Imperial Family |
| 11 | 18 April 1943 | Isoroku Yamamoto | (1884-1943) | Niigata |
| 12 | 21 June 1943 | Osami Nagano | (1884-1947) | Kochi |
| 13 | 31 March 1944 | Mineichi Koga | (1885-1944) | Saga |