Sesheshet, occasionally known as Sesh, was the mother of King Teti, the first and founding king of the Sixth Dynasty of Ancient Egypt. She was instrumental in enabling her son to gain the throne and reconciling two warring factions of the royal family.

In 2008, archeologists discovered what is believed to have been her pyramid.

Sesheshet was a grandmother of King Pepi I. Queen Iput I, Teti's wife, was a daughter of King Unas, the last king of the Fifth Dynasty. The dynasty that arose from Teti is considered part of the Old Kingdom of Egypt, a term designated by modern historians.

There was no break in the royal lines or the location of the capital from its predecessors, but significant cultural changes occurred to prompt the designation of different periods by scholars.

Until the recent rediscovery of her pyramid, little contemporary evidence about Sesheshet had been found. Her estates under the title King's Mother are mentioned in the tomb of the early Sixth Dynasty vizier Mehi, and she is referenced in passing as the mother of Teti in a remedy for baldness in the Ebers Papyrus.

Teti named his daughters after his mother.

On 8 November 2008, Egypt's chief archaeologist, Zahi Hawass, then secretary general of the Supreme Council of Antiquities (2002–2011), announced that Sesheshet was entombed in a 4,300-year-old, topless pyramid at Saqqara that measures 5 metres (16 ft) tall. Hawass stated that this may be Saqqara's most complete subsidiary pyramid. The tomb is number 118 among the ancient pyramids discovered so far in Egypt. The largest part of its 2 metres (6.6 ft) wide casing was built with a superstructure 5 metres (16 ft) high.

Hawass's archaeological team began excavating the site in 2006. The discovery of the pyramid was made in September 2008 with the unearthing of the structure from the sand. The structure originally reached 14 metres (46 ft) in height, with sides 22 metres (72 ft) long.