The Priest: The unnamed main character in the novel, the priest is on the run from the authorities, who will kill him if they catch him. A "whisky priest," and not the finest example of his profession, he is an alcoholic who has also fathered a child. In his younger days he was smug and self-satisfied. Now as a fugitive, he feels guilt for his mistakes and sins. Nevertheless, he continues to perform his priestly functions (often in great difficulty and sometimes reluctance) and it is his determination to attend to the spiritual needs of a dying man that leads to his eventual capture and death.
The Lieutenant: The lieutenant is the chief adversary of the priest. He hates the church because he thinks it is corrupt, and he pursues the priest ruthlessly. He takes hostages from the villages and kills them when he feels it is necessary. However, the lieutenant is also idealistic, and believes in radical social reform that would end poverty and provide education for everyone. He is capable of acts of personal kindness, as when he gives the priest (whom he believes to be a destitute drunkard) money on leaving the jail.
The Mestizo: The mestizo is the half-Indian peasant who insists on guiding the priest to Carmen. The priest knows that the mestizo will at some point hand him over to the authorities. The mestizo encounters the priest again in the prison, but prefers to wait for the right moment to betray him, which he does when leading him to the dying American.
Maria: Maria is the mother of Brigitta, the priest’s daughter. She keeps brandy for the priest and helps him evade the police when they come to her village looking for him. Although she shows support when the "whisky priest" reappears, the narrative leaves the character of Maria incomplete... with implications of resentment.
Brigitta: The young daughter of Maria and the priest.
Padre José: A priest who obeyed the government’s instructions and took a wife. He is dominated by her and has lost both the respect of the town and his self-respect. He refuses to do any priestly duties, even when people beg him to, because he fears the authorities.
Mr. Tench: Mr. Tench is a dissatisfied English dentist who longs to return from Mexico to England. He befriends the priest, whom he meets at the quayside, and later witnesses his death.
Coral Fellows: The thirteen-year-old daughter of Captain and Mrs. Fellows. She befriends the priest and offers refuge to him for the future. Her fate at the end of the novel is not revealed. Her parents have promised each other not to talk about her again.
Captain Fellows: A happy Englishman who works on a banana plantation who is displeased to find that the priest has taken refuge in his barn.
Mrs. Fellows: The wife of Captain Fellows. She is neurotic and fearful and hates life in Mexico.
The Woman: The unnamed woman reads to her children the story of Juan and his martyrdom. The Catholic faith is important to her and she wants her children to take an interest in it.
Luis: This young boy shows little interest in the story his mother reads to him, but his interest is awakened by the news of the priest's death.
The Gringo: An American fugitive called James Calver, he is wanted for murder and bank robbery.
The Chief of Police: Mostly concerned with playing billiards and assuaging his own toothache, he doesn't share the Lieutenant's idealism and wilfully breaks the law.
The Lehrs: Mr. Lehr, a widower, and his sister, Miss Lehr, are an elderly couple who allow the priest to stay with them after he crosses the state border. They are Lutherans, and have little sympathy for Catholicism, although they treat the priest with kindness.
Juan: Juan is a character within a story that the unnamed woman reads to her family. Juan is a young Mexican man who enters the priesthood, lives a pious life and faces his death by firing squad with great courage.