The distinctive voice of the omniscient narrator of The Mayor of Casterbridge sets the novel's tone, as the narrator tells a complicated, tangled, and eventful story in which characters are blown around by fate and happenstance. Hardy’s narrator is highly present in the story, setting a sympathetic and didactic tone for the book. The voice of his narrator reflects the moral system at the center of the novel, where the good are rewarded and the bad punished (though not always to a fair degree). At times, the narrative tone is almost elegiac and mournful, as the narrator seems to bemoan the cruelty of fate and the regrettable consequences of characters' actions.
The tone of the novel is significantly influenced by moments in which the third-person narrator incorporates some of the personal and judgmental elements of a first-person narrator. Various interjections (observations, parenthetical judgements, commentary by the narrator) saturate the novel with an opinion and a certain moral positioning. The attitude the narrator takes to the behavior of Hardy's characters establishes the didactic and principle-oriented tone of the book. Hardy’s readers are invited to draw their own conclusions about the disasters and the joys of the novel, but the narrator’s high-handed and moralistic tone also influences how actions and choices are represented and can be understood. Without the omniscient narrator's framing, for example, Michael Henchard's actions might seem purely evil instead of nuanced, complex, and influenced by circumstance.