last king of the 5th dynasty (Egypt, ancient) (c. 2465–c. 2325 BCE) of ancient Egypt (Egypt, ancient) and the first pharaoh to inscribe the interior of his pyramid at Ṣaqqārah with religious and magical texts known as Pyramid Texts. According to later king lists, Unas was the last ruler of the 5th dynasty, but the innovations in his pyramid complex and the use of blocks from his predecessor's monuments in his own pyramid have led some to consider him the founder of the 6th dynasty (Egypt, ancient) (c. 2325–c. 2150 BCE), or at least a transitional ruler.

The reliefs and texts in Unas's burial chamber and other rooms were meant to assist the deceased pharaoh in the afterlife. The texts preserve many archaic liturgies and are a valuable compendium of early Egyptian beliefs. Unas's causeway, connecting his pyramid complex on the high desert with the valley temple near the edge of cultivation, contained interesting reliefs that probably recount events of his reign. His texts depict the transport of granite blocks from Aswān for the king's temple. The first known battle scene in Egyptian relief, probably recording a raid against the Bedouins (Bedouin) of the northeast frontier, also appears. Trade with Syria and Palestine is attested by scenes of ships carrying foreign peoples. Finally, a fragmentary but vivid scene of starving people depicts a famine; some scholars suggest that it describes Unas's aid to famished desert tribesmen. The work of the complex represents a high point of subject variety in Old Kingdom (Egypt, ancient) (c. 2575–c. 2130 BCE) scenes.

Unas's daughter married his successor, Teti, whom the ancient sources considered the founder of the 6th dynasty.