Sonic was born on a small island called Christmas Island. But his love for adventure called him away and he has visited so many different places on Earth that he doesn't really have a place he considers to be home.
Christmas Island (クリスマス島,Kurisumasu tō?) is the place where Sonic the Hedgehog was born. No other information is known or ever given about this island, nor it has ever been referred to in video game appearances.
Christmas Island is one of the few instances in which a specific real-world location has been referred to in the Sonic video game continuity. It may refer to either Christmas Island, Australia, or to Kiritimati.