In terms of actually _known_ in the meaning meant (people have some awareness of what they did) probably the Pharaohs Djoser (born 2686BCE) who built the stepped pyramid at Saqqara.
Maybe Gilgamesh, who may well have been a historical king of Uruk sometime between 2900 – 2350 BCE.
Enmebaragesi[1] probably existed around 2600 BCE but not much is known about him other than he was a King of Kish.
Figures in the old testament Bible are hard to track but the stories of Nimrod (grandson of Noah) seems to have been placed around 2000 BCE
If you mean "Who is the earliest known recorded individual in human history?" wikipedia says "The name "Kushim" is found on several Uruk period (c. 3400–3000 BC) clay tablets used to record transactions of barley." [0]
