Merenre Nemtyemsaf I (reigned 2287-2278 BC) was the fourth king of the Sixth dynasty of Egypt. His nomen, theophorically referring to Nemty, was formerly read as Antyemsaf, a reading now known to be incorrect.
Merenre was a son of Pepi I and Ankhesenpepi I, and grandson of the female vizier Nebet and her spouse Khui.
While Merenre Nemtyemsaf was once believed to have served as a brief co-regent to his father Pepi I Meryre before ruling in his own right, the publication of the South Saqqara Stone annal document in 1995 by Vassil Dobrev and Michel Baud shows that Merenre directly succeeded his father in power with no interregnum or coregency. The badly damaged document preserves the record of Pepi I's final year—his 25th Count and proceeds immediately to the first year count of Merenre Merenre shared his father's fascination with Nubia and continued to explore deep into the region. He also began a process of royal consolidation, appointing Weni as the first governor of all of Upper Egypt and expanding the power of several other governors. While he was once assumed to have died at an early age, recent archaeological discoveries discount this theory. Two contemporary objects suggests that Merenre's reign lasted slightly more than a decade. The South Saqqara Stone Annals preserves his Year after the 2nd Count whereas Merenre's Year after the 5th Count (Year 10 if the count was biennial) is attested in a quarry inscription from Hatnub Inscription No.6, according to Anthony Spalinger.