Sekhemib-Perenma'at (or simply Sekhemib), is the Horus name of an early Egyptian king who ruled during the 2nd Dynasty. Similar to his predecessor, successor or co-ruler Seth-Peribsen, Sekhemib is contemporarily well attested in archaeological records, but he does not appear in any posthumous document. The exact length of his reign is unknown and his burial site has yet to be found.

Sekhemib's name is known from seal impressions and from inscriptions on vessels made of alabaster and breccia. They were found in the entrance of Peribsen's tomb at Abydos, in the underground galleries beneath the step pyramid of (3rd Dynasty) king Djoser at Sakkara and on one excavation site at Elephantine.

Sekhemib's serekh name is notable, as it is the first in Egyptian history that was extended by an epithet. Beside the first name, Sekhem-ib, several seal impressions and stone vessel inscriptions show the epithet Perenma'at inside the serekh. Sekhemib used both name forms, the single horus name and the double name, at the same time. Egyptologists such as Herman te Velde and Wolfgang Helck think that the double name of Sekhemib came in use when the Egyptian state was split into two independent realms. It seems that Sekhemib tried to stress the peaceful political situation prevailing in Egypt at the time. An increased form of such a double name was created and used by a successor of Sekhemib, king Khasekhemwy. This king also used a double name and even placed Horus and Seth together as protective deities atop his serekh. Khasekhemwy had tried to express peace and reconciliation between Upper- and Lower Egypt with his unusual serekh, too.

The historical figure of Sekhemib is the subject of investigation and discussions by Egyptologists and historians to this day. The contradictory findings allow room for plenty of interpretations and theories.

Egyptologists such as Walter Bryan Emery, Kathryn A. Bard and Flinders Petrie believe that Sekhemib was the same person as king Peribsen, a ruler who had connected his name with the deity Seth and who possibly ruled only Upper Egypt. Emery, Bard and Petrie point to several clay seals that were found in the tomb entrance of Peribsen's necropolis. Sekhemib's tomb has not yet been found.

In contrast, Egyptologists such as Hermann Alexander Schlögl, Wolfgang Helck, Peter Kaplony and Jochem Kahl believe that Sekhemib was a different ruler to Peribsen. They point out that the clay seals were only found at the entrance area of Peribsen's tomb and that none of them ever shows Peribsen and Sekhemib's names together in one inscription. They compare the findings with the ivory tablets of king Hotepsekhemwy found at the entrance of king Qaa's tomb. Therefore, Schlögl, Helck, Kaplony and Kahl are convinced that Sekhemib's seals are merely proof that Sekhemib buried Peribsen.

Egyptologists such as Toby Wilkinson and Helck believe that Sekhemib and Peribsen could have been related. Their theory is based on the stone vessel inscriptions and seal impressions that show strong similarities in their typographical and grammatical writing styles. The vessels of Peribsen for example show the notation "ini-setjet" ("tribute of the people of Sethroë"), whilst Sekhemib's inscriptions note "ini-chasut" ("tribute of the desert nomads"). A further indication for a relationship between Peribsen and Sekhemib is the serekh-name of both, as they both use the syllables "per" and "ib" in their names.

Egyptologists such as Helck identify Sekhemib with the Ramesside cartouche name “Wadjenes” and equate Peribsen with a king named Senedj. Egyptologist Dietrich Wildung thinks alike and identifies Sekhemib with the nebty name Weneg-Nebty and Peribsen with Senedj.