C. Auguste Dupin -
Asavvy and learned Parisian who helps the city's police solve crimes. Dupin uses psychology to foil the plans of a thief and uncover a stolen letter that the police of Paris could not uncover by conventional investigations.
A friend of Dupin. In awe of Dupin's brilliance, the narrator faithfully recounts Dupin's explanations without doubting or challenging him.
The Prefect of the Paris police. Limited by his conventional police training, Monsieur G—— depends on Dupin's assistance in peculiarly difficult crimes, and his own general competence highlights Dupin's superior abilities.
A government official and the thief of the letter. Minister D—— 's ability to outwit the police in his crime proves he is a worthy adversary for Dupin.