The Supreme Commander-in-chief of the Imperial Japanese Army and Navy (Japanese: 大元帥陸海軍大将, romanized: Dai-gensui-riku-kai-gun-taishō) was the highest rank of the Imperial Japanese Army and the Imperial Japanese Navy from 1872 to 1945, when the Empire of Japan was dissolved. The rank was only ever held by the Emperor of Japan as Supreme commander-in-chief of the Imperial Japanese Armed Forces and, separately, the highest-ranking officer in each of the military branches. It formally became obsolete in 1947 when the Imperial Japanese military was abolished.

The term originated in the Chinese military title da yuan shuai (大元帥), a title higher than yuan shuai (元帥, pronounced gensui in Japanese).

Decree No. 252 by the Dajokan, dated 7 September 1872 first made formal mention of the rank of dai-gensui; however, no appointments to the rank were made before the rank was abolished along with that of gensui on 8 May 1873. By "Draft Ordinance No. 142" of the Constitution of the Empire of Japan (Chapter 1 Part 1) of 30 September 1889, the Emperor was officially given the rank of dai-gensui and installed as supreme commander of the Army and Navy.

The kanji characters also refer to a Buddhist deity, Daigensui Myō'ō (大元帥明王), a Wisdom King worshipped by the Imperial Court since Emperor Ninmyō and by the Shingon sect, for its legendary miraculous power to quell foreign enemies and rebellions, just like a military leader.

The insignia of a dai-gensui were identical to those of a full general, with the addition of the gold imperial chrysanthemum.

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  Army collar insignia
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  Army shoulder insignia
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  Naval shoulder insignia
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  Naval collar insignia
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  Naval sleeve insignia
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  Naval sleeve insignia

Portrait	Name (birth–death)	Term of office			Ref.
		Took office	Left office	Time in office
	Meiji Emperor (1852–1912)	1872 1889	1873 30 July 1912 †	23–24 years
	Taishō Emperor (1879–1926)	30 July 1912	25 December 1926 †	13–14 years
	Shōwa Emperor (1901–1989)	25 December 1926	2 September 1945	18–19 years

• Other pronunciations of the characters 大元帥
  • Dayuanshuai in Chinese
  • Taewonsu, the Korean equivalent
• The higher rank of gensui (元帥)
  • Yuanshuai, the original Chinese title
  • Wonsu, the Korean equivalent

• Donald Keene, Emperor of Japan, Meiji and his World 1852–1912