Corsica was no doubt occupied by small groups starting in the 7th millennium BC.
The fist known human is the "Lady of Bonifacio" (ca. 6570 BC).

Man occupied the entire island during the Neolithic Era, developing agriculture and animal husbandry and organising villages.
There were certainly regular contacts with the nearest Mediterranean coasts. A brilliant civilisation rose in the 3rd millennium.
They knew how to cast copper, sculpted hundreds of menhirs (standing stones), some of which are veritable statues, and built huge stone constructions (castelli, torri). Everything points to an organised society, very close to the Sardinian Nuragic civilisation.