Nobody knows. Until recent centuries Jews, Christians, and Muslims believed the world was created a few thousand years ago. They believed that Adam and Eve were the first persons, and were created about 3616 to 5592 BC according to various calculations (the medieval Alfonsine tables gave 6484 or 6984 BC).

But members of other societies and believers in other religions could believe that the world was much older than that. Thus some societies claimed that legendary and mythological kings reigned tens or hundreds of thousands of years earlier than that.

Sumerian king lists claimed that mythological kings ruled for 241,200 years before a great flood about 2900 BC. Egyptian king lists listed god kings ruling for tens of thousands of years before mortal kings.

Hindusim believes in a vastly old universe millions and billions of years old.

Thus some persons claimed to be historical clearly lived in a prehistoric past. But what about persons who lived closer to the dawn of written records? How can we tell which were real and which were imaginary? With difficulty and controversy.

I would guess that the oldest person in the historical record did not live much earlier or later than Menes, the legendary first king of all Egypt. The reign of Menes was dated to various dates between about 2320 BC to 5702 BC by 19th century Egyptology and is now dated to about 3050 or 3100 BC.

So the oldest real historical person may have been Menes or someone else who lived about 3000 to 3100 BC.