The Hashihaka kofun (箸墓古墳) is a megalithic tomb (kofun) located in Sakurai, Nara Prefecture, Japan. The Hashihaka kofun is considered to be the first large keyhole-shaped kofun constructed in Japan and is associated with the emergence of the Yamato Kingship.

The Imperial Household Agency designates the Hashihaka kofun as the tomb of Princess Yamato Totohi Momoso, the daughter of the legendary Emperor Kōrei. Researchers in 2013 conducted the first-ever on-site survey of the Hashihaka kofun after being granted access by the Imperial Household Agency. The actual burial site is unknown, but the Imperial Household Agency has designated it as the tomb of Oichi no Haka, the seventh Kōrei princess, Princess Yamato Totohi Momoso. Also, since the research of Shinya Kasai, there is a theory that it may be the tomb of Himiko, the queen of Yamatai (Yamataikoku). The moat around the site has been designated as a historic site by the government, Part of the pond has been selected as one of the 100 best reservoirs as "Chopenaka Great Pond.

The name Hashihaka translates as "chopstick grave" and refers to a mythical love affair between Princess Yamato Totohi Momoso and the kami of sacred Mount Miwa, which ended with the princess stabbing herself to death with a chopstick.

It is the main tumulus of the Alluvial fan zone at the northwestern foot of Miwa in the southeastern Nara Basin, and is located in the Chopashinaka district of the Garimuku site. It is located in the city. It is considered to be one of the oldest burial mounds of the emergence period.^{[clarification needed]}

The date of construction was determined by archaeological dating of earthenware (Doji pottery) excavated from the surrounding dugouts and by radiocarbon dating. According to Yamataikoku, there is a theory that places the date in the middle to late 3rd century, close to the year of death of Himiko (not far from 248) in the Yamataikoku. On the other hand, some date it to the mid-4th century or later, because recent carbon-14 dating methods have shown that the date is estimated to be 50–100 years older than the actual date, and because the size and style of the tomb is different from that described in the Wajinden (Treatise on the Wa People).

Currently, the Imperial Household Agency manages the tomb as a mausoleum, and researchers and the public are not allowed to enter the tumulus freely. Wajaku-no-Tsukihime-no-Mikoto is the sister of Emperor Kōgen, the grandfather of Emperor Sujin in Nihon Shoki (The Chronicles of Japan). Oichi is the name of the place where the tomb is located. In the Kojiki (Records of Ancient Matters or An Account of Ancient Matters), she is named Yamato Tomomosobime.

In the world of archaeology, the theory that "Queen Himiko = Wajaku-no-Hyakusohime-no-mikoto" was proposed by Shinya Kasai, who had advocated the theory of the Yamatai Internal Theory since the Taishō period, and later developed into the theory that "the tomb of Chopstick Tomb = Himiko's tomb", which was pioneering research leading to the discussions of today.

The origin of the name is based on a legend that a chopstick pierced the pubic region of Princess Hyakuso, causing her to die. In the Nihon Shoki, Soshin, September 10, there is a story as follows. It is generally referred to as the legend of Mount Miwa.