Hiram Bingham III (November 19, 1875 – June 6, 1956) was an American academic, explorer and politician. In 1911, he publicized the existence of the Inca citadel of Machu Picchu which he rediscovered with the guidance of local indigenous farmers. Later, Bingham served as the 69th governor of Connecticut for a single day in 1925—the shortest term in history. He had been elected in 1924 as governor, but was also elected to the Senate and chose that position. He served as a member of the United States Senate until 1933.

Bingham was born in Honolulu, Hawaii, the son of Clara Brewster and Hiram Bingham II (1831–1908), an early Protestant missionary to the Kingdom of Hawai'i. He was also the grandson of Hiram Bingham I (1789–1869) and Sybil Moseley Bingham (1792–1848), earlier missionaries. Through his mother's side he was a descendant of William Brewster, a Mayflower passenger. He attended O'ahu College, now known as Punahou School, from 1882 to 1892.

Bingham went to the United States in his teens in order to undertake higher education, entering Phillips Academy in Andover, Massachusetts, from which he graduated in 1894. He earned a B.A. degree from Yale College in 1898, a degree from the University of California, Berkeley, in 1900, where he took one of the first courses in Latin American history offered in the United States, and a Ph.D. from Harvard University in 1905. Since Harvard at the time did not have a specialist in Latin American history, Edward Gaylord Bourne of Yale served as the examiner for Bingham's qualifying exams. While at Yale, Bingham was a member of Acacia fraternity.

In his first academic position, he taught history and politics at Harvard. He next served as preceptor (teacher) under Woodrow Wilson at Princeton University. Princeton "did not much favor Latin American history." But in 1907, when Yale sought a replacement for Bourne, who had died an early death, it appointed Bingham as a lecturer in South American history. He became one of the pioneers in the U.S. of teaching and research on Latin American history. In 1908, he published an assessment of the field's prospects, "The Possibilities of South American History and Politics as a Field for Research," in which he surveyed library and archival resources in the U.S. as well as in South America. From 1924, he was a member of the Acorn Club.

Bingham was not a trained archaeologist. But while he served as a lecturer and professor in South American history at Yale, he journeyed to South America and rediscovered the largely forgotten Inca city of Machu Picchu. In 1908 he had served as a delegate to the First Pan American Scientific Congress at Santiago, Chile. On his way home via Peru, a local prefect convinced him to visit the pre-Columbian city of Choquequirao. Bingham published an account of this trip in Across South America; an account of a journey from Buenos Aires to Lima by way of Potosí, with notes on Brazil, Argentina, Bolivia, Chile, and Peru (1911).

Bingham was thrilled by the prospect of unexplored Inca cities, and organized the 1911 Yale Peruvian Expedition, one of the objectives of which was to search for the last capital of the Incas. Guided by locals, he rediscovered and correctly identified both Vitcos (then called Rosaspata) and Vilcabamba (then called Espíritu Pampa), which he named "Eromboni Pampa". He did not correctly recognize Vilcabamba as the last capital, instead continuing onward and misidentifying Machu Picchu as the "Lost City of the Incas". Decades later, Bingham's oversight was rectified by the Andean explorer Vince Lee, whose detailed research proved that Vilcabamba was indeed the Incas' last capital.

On July 24, 1911, Melchor Arteaga led Bingham to Machu Picchu, which had been largely forgotten by everybody except the small number of people living in the immediately neighboring valley. In addition, Cusco explorers Enrique Palma, Gabino Sanchez, and Agustín Lizárraga are said to have reached the site in 1901. In 1902 Peruvian explorer Agustín Lizárraga led an expedition to the area now known as Machu Picchu. After several hours of clearing undergrowth they reached the stone structures of the citadel, during that visit Lizárraga marked his surname and the year, "A. Lizárraga 1902", in charcoal on the central window of the Temple of the Three Windows. Bingham found the surname of Lizárraga and the 1902 date on the temple. Initially disappointed, he documented in his pocket field journal: "Agustín Lizárraga is discoverer of Machu Picchu and lives at San Miguel Bridge just before passing. However, while Bingham initially acknowledged Lizárraga as the discoverer in his early writings and speeches, including Inca Land (1922), he gradually downplayed Lizárraga's role until, in his final version of the story, Lost City of the Incas (1952), Bingham claimed to have found the site himself. Two local missionaries, Thomas Payne and Stuart McNairn, are credited by descendants with having climbed to the ruins in 1906.^{[citation needed]}

Bingham returned to Peru in 1912, 1914, and 1915 with the support of Yale and the National Geographic Society. In Lost City of the Incas (1948), Bingham related how he came to believe that Machu Picchu housed a major religious shrine and served as a training center for religious leaders. Modern archaeological research has since determined that the site was not a religious center but a royal estate to which Inca leaders and their entourage repaired during the Andean summer.