William Wilson (real): He is the protagonist of this story, and also the narrator. He says he has made a lot of very bad crimes, and he says he shouldn't mention his name, because he is hated and known all around the world because of his evil life. He says his family has always made men of strong imagination and violent temper, and he is no exception. He was born on January 19th, 1813.

William Wilson (mimic): He is a child the protagonist met when he was a child, with the same name and same birth date of the real William Wilson, and always evaded William Wilson from controlling him. One day the protagonist noticed how this person started imitating him, following exactly what he did, but the only thing that could differentiate them both is that the mimic wouldn't speak louder than a whisper. He was born aswell on January 19th, 1813.