Admiral Yamamoto Gonnohyoe (山本権兵衛 October 15, 1852–December 8, 1933, also called Gombei) was a Japanese military leader and the 16th (February 20, 1913–April 16, 1914) and 22nd (September 2, 1923–January 7, 1924) Prime Minister of Japan.

He was born in Satsuma Province (now Kagoshima Prefecture) as the son of samurai who served the Shimazu clan. After he fought in the Boshin war as a Satsuma samurai, he studied in several governmental schools in Tokyo successively. He graduated from the Naval Academy in 1874. He was Minister of the Navy from 1898 to 1906, during those years he prepared the Russo-Japanese war and showed strong leadership in the Japanese navy. He found the talent of Togo Heihachiro as an admiral and appointed him chief admiral of the Grand Fleet of the Imperial Japanese Navy.

He became a count on September 21, 1907.

As a politician he pursued not only the profit of military offices but attempted to keep the balance between them and other parts of the government. He also understood the public claim for democracy and constitutional governance. During his first office as the prime minister, he abolished the rule that both the minister of the Navy and the minister of the Army should be military officers who had not retired yet. But he resigned because of the Siemens scandal, a scandal in which he had received a bribe from Siemens concerning with the naval ships' purchase.

In 1923 he was again appointed prime minister and showed leadership in the restoration of Tokyo which had been heavily damaged with the Great Kanto earthquake. He attempted to reform the electoral system and to give the vote to all adult men without limitation. But he should have resigned again. On December 27, Namba Daisuke tried to assassinate the Prince Regent Hirohito. All the cabinet resigned with the idea it was their responsibility for not preventing this case.

Shortly before his death in 1933, he was awarded the Supreme Order.