Pepi I Meryre was an Ancient Egyptian pharaoh, third king of the Sixth Dynasty of Egypt, who ruled for over 40 years at the turn of the 24th and 23rd centuries BC, toward the end of the Old Kingdom period. He was the son of Teti, the founder of the dynasty and ascended the throne only after the brief intervening reign of the shadowy Userkare. His mother was Iput, who may have been a daughter of Unas, the final ruler of the preceding Fifth Dynasty. Pepi I, who had at least six consorts, was succeeded by his son Merenre Nemtyemsaf I, with whom he may have shared power in a coregency at the very end of his reign. Pepi II Neferkare, who might also have been Pepi I's son, succeeded Merenre.
Several difficulties accumulated during Pepi's reign, beginning with the possible murder of his father and the ensuing reign of Userkare. Later, probably after his twentieth year of reign, Pepi faced a harem conspiracy hatched by one of his consorts who may have tried to have her son designated heir to the throne, and possibly another conspiracy involving his vizier at the end of his reign.