The narrator of 'The Tell-Tale Heart' is an unnamed character who presents a chilling first-person account of his descent into madness. This unreliable narrator claims to be sane, yet his obsessive fixation on an old man's vulture-like eye drives him to commit murder, revealing deep psychological complexities and themes of guilt and paranoia. The use of first-person narration enhances the story's tension and allows readers to experience the narrator's disturbed mind intimately.