He wasn't French, he was Corsican. His name and his family language  were Corsican,  which is basically the Tuscan language (aka "Italian", but not really). His ancestry was Corsican/Tuscan and Ligurian/Lombard.

Corsica had only been annexed to France the same year Napoleon was born. Up until then it had been independent for a brief period, and before that a Genoese possession for most of the previous centuries.