I've seen claims for Iry-Hor and Menes. By "historical figure" I mean a person whose name appears in writing and who was reasonably likely to have actually lived. Meaning Adam doesn't count.
If writing was invented circa 3100 BC, are we likely to find a named person who pre-dates Iry-Hor?
Kushim, an accountant from Uruk in Mesopotamia, circa 3100-3000 BC. There's a clay tablet which has been translated to say "29,086 measures barley 37 months (signed) Kushim." Not a famous person by any means, but potentially the oldest written record of the name of a real person.
This claim has been disputed, however, as the tablet cannot be dated precisely, and it is also uncertain whether "Kushim" instead is a title or means something else entirely.
There's another tablet, also dated from around 3100 BC, which is more clearly referring to named people, about Gal-Sal and his slaves En-pap X and Sukkalgir.