Dr. Bernard Rieux is the narrator of The Plague. He is one of the first people in Oran to urge that stringent sanitation measures be taken to fight the rising epidemic. A staunch humanist and atheist, Dr. Rieux has little patience with the authorities' foot-dragging in response to his call for action. His actions and personality imply that he believes in a personal as well as a social code of ethics. When Oran is placed under quarantine, Dr. Rieux continues to doggedly battle the plague despite the signs that his efforts make little or no difference. Although he is separated from his wife, he does not allow his personal distress to distract him from his battle to relieve the collective social suffering wrought on the confused and terrified population of Oran.
Jean Tarrou is the author of the account that Dr. Rieux uses to give greater texture to his chronicle of the plague. Tarrou is vacationing in Oran when the epidemic requires a total quarantine of the city. As an outsider, his observations on Oran society are more objective than those of a citizen of the city. Tarrou's beliefs about personal and social responsibility are remarkably similar to those of Dr. Rieux, but Tarrou is far more philosophical. He does not believe in God, so he does not believe in the illusion of an intrinsic rational and moral meaning in death, suffering, and human existence. For him, human existence gains meaning only when people choose freely to participate in the losing, but noble struggle against death and suffering. Tarrou contributes to the anti-plague effort in accordance with his code of ethics.
Joseph Grand is an elderly civil servant in Oran. When he accepted his job as a young man, he was promised the opportunity for promotion, but, over the years, he never actively pursued it. Therefore, he remained in the same job for decades. His marriage also settled into a daily humdrum. Eventually, Grand's wife Jeanne tired of the monotonous routine and left him. Over the years, Grand has tried to write her a letter, but he suffers from an intense anxiety over finding the "right words" to express himself. This anxiety also hinders his literary pursuit. Grand is trying to write a book, but he wants to create the perfect manuscript, so he has never gotten beyond the opening line.
Raymond Rambert is a journalist from Paris. He comes to Oran to research the sanitary conditions in the Arab population, but the sudden, unexpected total quarantine of Oran traps him in the city. He desperately struggles to find some method of escape from Oran to rejoin his wife in Paris.
Cottard is suspicious, paranoid, and mercurial. In the past, he committed a crime that he does not name, so he constantly fears arrest and punishment. When Oran falls under total quarantine, Cottard is happy because he no longer feels alone in his state of constant fear. Moreover, the plague occupies the authorities entirely, so he does not fear arrest. He engages in the profitable smuggling trade during the epidemic and eschews all responsibility to help fight the disease.
Father Paneloux is a Jesuit priest in Oran. Early during the epidemic, he delivers a sermon to his confused, frightened congregation declaring that the plague is a God-sent punishment for their sins. As the plague rages on, he modifies this stance, seeing the Plague as a supreme test of faith.
M. Othon is a conservative magistrate in Oran. Because he is a judge, Tarrou considers him "public enemy number one."
Jacques is M. Othon's small son. After he contracts the plague, he is the first to receive some of Dr. Castel's plague serum.
Castel, an elderly doctor, is the first person to utter "plague" in reference to the strange, fatal illness that appears after all the rats in Oran die. He and Dr. Rieux struggle with the authorities' denial and foot-dragging when they urge that stringent sanitation measures be taken to combat a possible epidemic.
Dr. Rieux's asthma patient serves as mouthpiece for the changing whims of Oran society during the prolonged epidemic.
Dr. Richard is the chairman of the medical association in Oran. When Rieux and Castel suggest that the strange illness is the bubonic plague, Dr. Richard does not want to believe it. He prefers to adopt a "wait-and-see" attitude instead of "alarming the public" with immediate, decisive action.
The Prefect drags his feet when Rieux and Castel urge him to enact stringent sanitation measures to combat a possible epidemic of bubonic plague.
M. Michel is the concierge for the building where Rieux works. He is the first victim of the plague.