Zorba the Greek tells the story of a Greek man, an unnamed narrator, who goes on a great journey of self-discovery and enlightenment with an older man named Alexis Zorba. The story begins in a café in Piraeus in the year 1916, sometime after the narrator's closest friend, Stavridakis, leaves him to rescue persecuted Greeks in the Caucasus. This is where the narrator meets Zorba for the first time. The narrator has plans to reopen an abandoned lignite mine on the island of Crete, and Zorba suggests that he can come along, as he makes very good soup. The narrator agrees, as he finds Zorba odd and charming, and this is where the adventure begins.
The narrator reflects on how he wants to escape his bookworm lifestyle and move to a place where he can live and work amongst peasants. He and Zorba board the ship to Crete, as Zorba tells the narrator, now referred to as "boss," that he used to be a rebel fighter during the Cretan revolution, and how man is born blind and will die blind until he has seen the liberation of an entire people.
They dock and step off the ship into the village, and Zorba states that as long as they can find a widow, they'll be taken care of. When asking at a café where they could find lodging, they discover that a widow name Madame Hortense runs an inn in the village. They travel to the inn, where they ask for two rooms to stay the night. The narrator takes the next morning to travel alone around the village, seeing the sights, and reading his Dante by the sea, until he is at last found by Zorba at midday. They return to Madame Hortense's, where they are confronted by a village elder, Mavrandoni, who mentions that it is uncouth for them to stay at the hotel of a lady. He offers them a place to stay, but they refuse, and go on to enjoy lunch with Madame Hortense. They have a joyful and hearty lunch with Madame, and she tells the story of how at one time she controlled the four world powers with her beauty. The English, Russian, Italian, and French admirals, with their fabulous beards and scents, had been won over by Madame Hortense, and she convinced them not to bomb Crete. This prompts Zorba to begin calling her Bouboulina, who was a heroine of the war of independence. It is this night that Zorba takes her as his lover.
The next morning, Zorba and the narrator talk about women and love, and Zorba begins his work as foreman of the mine operation. The narrator is amazed by Zorba's spirit, and how he sees everything as though for the first time. He is older and well-traveled, and tells the narrator stories of the places he has been and the things he has seen. In the early stages of the mining operation, the narrator goes with Zorba to the mine, as he wants to speak to the workers and live and work amongst them. Zorba, however, advises against this, fearing that the narrator's socialist beliefs would result in him being taken advantage of by the workers. Later that day, the narrator makes a pledge to himself to let go of his metaphysical predisposition and try to live firmly in the real, physical world.
Zorba and the narrator engage in further conversation about life and religion, and of how the narrator wishes to open people's eyes to a better kind of world. He works manically that night on his Buddhist manuscript, imagining the better world that he spoke of in vivid detail. Zorba tells the narrator that he believes there to be three types of men: those that turn their food into fat and manure, those that turn their food into work and good humor, and those that try to turn their food into God. He says that he believes the narrator tries his best to turn his food into God, and becomes very frustrated when he fails. Zorba then tells the story of a Russian man he once knew, whom he communicated with through dancing. The narrator thinks of how he wishes he could wipe away all the traditional learning he had and attend Zorba's school to learn what he describes as "the great, the real alphabet!" He feels his life has been wasted, and wishes that he could be more like Zorba, who has found the real truth of life.
One morning, the narrator finally decides to pen a letter to his old friend Stavridakis, telling him how he is giving up his bookworm life and embracing the world on Crete. He reminisces on the good times they had together, and admits that he loved Stavridakis very deeply. This letter relieves him of some ill will, and he decides to go with Zorba for a walk in the rain. They stop in the café, soaked to the bone, and this is the first sighting he has of the mesmerizing widow. Mavrandoni's son Pavli is deeply in love with the widow, saying at once that if she will not marry him, he will kill himself. They stop for a while to talk to Mimiko, the village simpleton, and Zorba insists that the narrator should sleep with the widow, as he believes it is the greatest sin to refuse to share a bed with a woman. The narrator nonetheless refuses, and they return to their beach encampment.
The next morning, the narrator accompanies Zorba and the workers to the mine, and he watches Zorba work for a while. At the miners' lunch break however, Zorba hears a strange sound and ushers all the workers out of the mine, after which the entire gallery collapses. The workmen eat with Zorba and the narrator, and one of the workers thanks Zorba for saving all of their lives.
The narrator continues his Buddhist writings in an effort to exorcise the beautiful widow from his mind, while Zorba continues to encourage him to go to her, even on Christmas Eve. They share Christmas Eve dinner with Madame Hortense. On the first day of the new year, the narrator awakens happy and sets along the path toward the village, where he runs into the widow. He stands at the gate to her garden for a while, looking and imagining going in to be with her. He sits down beneath a flowering almond tree, where he is finally found by Zorba after some time.
They go to Madame Hortense's for a New Year's feast. Bouboulina reminisces on her youth in the great cities of the world. Zorba is working on a plan to craft a pulley line which would carry trees down the mountain at a gentle speed if placed along the right slope, but he must work quickly, as they are running out of money. After finally discovering the slope, Zorba announces that he must go to the town of Candia for three days to buy the supplies for his system, and the following morning he leaves for town.
The narrator receives a reply to his letter from Stavridakis, and he speaks of how his mission thus far has been a success, but if this is to be his last letter (implying his death), then he wishes the narrator to know that he loves him very dearly as well. Zorba has been gone for several days longer than he was meant to be, but the narrator receives a letter from him letting him know that everything is alright, and he has met a woman named Lola who he has been spending his time with. Later on, the narrator is approached by Bouboulina, who asks if there has been a letter from Zorba. The narrator, realizing that Bouboulina is very hurt, lies and tells her that the letter spoke only of her and how much Zorba misses her, and that when he returns he intends to marry her.
He walks back to the village with her, and they begin noticing a massive commotion occurring by the shore. He finds that Pavli, Mavrandoni's son, has killed himself because the widow did not wish to be with him. The villagers begin cursing the widow, taunting and demanding that someone kill her for the injustice. The narrator tries to defend her, asking how it is her fault that the boy is dead. Old Anagnosti contends that Pavli is better off, as life is nothing but suffering. Later that evening the narrator receives a basket of oranges from the widow, thanking him for standing up for her.
The narrator is overjoyed at the return of Zorba, as he stayed in Candia twelve days longer than he had intended. He has to break the news that he lied to Bouboulina about Zorba's letter, and Zorba is unhappy, saying that it's cruel to play with a woman's heart that way. Some time later, they begin to make their way to a monastery to negotiate the price of purchasing the forest that belongs to the monks. On the way they meet an ex-monk named Zaharia, who agrees to lead them to the monastery to speak to the abbot. They stay overnight so they can speak to the abbot, and in the night a young man is shot and killed. This tragedy allows Zorba to negotiate a lower price for the forest, presumably to avoid the news spreading about the young monk's violent death. Zaharia decides that the demon inside of him wants to burn down the monastery, and the Archangel Michael has demanded that he do so.
When they return to the beach, they are met by Madame Hortense, who calls Zorba cruel for leaving her waiting for so long. Deciding to appease her, Zorba apologizes, and that night they become engaged. Zorba tells the narrator the story of how he fought in the war, and killed a priest who was a Bulgarian soldier.
On Easter, the narrator and Zorba are waiting at their beach encampment for Madame Hortense to arrive, as they have set up a special meal for her. Eventually a young messenger comes to inform them that she is ill. Zorba goes to visit, and comes back to tell the narrator that she has a cold. Zorba goes to the village to dance, and at that moment the narrator finally decides to go to the widow to sleep with her. Afterward, he feels revitalized and swims in the ocean.
The next day a messenger comes, saying that Bouboulina wishes to see Zorba. Zorba went to work on the cable delivery system, so the narrator decides to go and visit Bouboulina instead. She seems very ill, and the narrator tells Mimiko to send for a doctor straight away.
After leaving Dame Hortense's house, the narrator finds that there is a commotion occurring because the widow is at the church. The villagers think it is disgraceful that she would show her face at the church after all she has done to the village, and so they decide to kill her. Manolakas brandishes his knife and raises it above the widow, but is held off by Zorba, who appears suddenly to defend the woman. The narrator, Zorba, and the widow begin running away, but the widow is caught by Mavrandoni, who cuts her head off with his knife. The narrator and Zorba return to their beach in horror and grief.
Three or four days of grieving later, Zorba goes to visit Dame Hortense. Her condition is worsening. When he returns and the narrator asks how Bouboulina is, Zorba replies that nothing is wrong and that she is going to die. Zorba decides to go for a walk, presumably to grieve, and he encounters Manolakas, who wishes to fight Zorba for dishonoring him at the church. The narrator steps in, however, just before they fight, and brings them both back to the beach to be friends and reconcile their disagreements.
The next morning, the narrator and Zorba go to visit poor Bouboulina, and old Anagnosti says he is not sure if they will find her still alive. She dies that morning, as the villagers ransack her home and steal her things. Zorba takes her parrot with him, gently closes her eyes, and leaves. Zorba asks the narrator questions about God when they return to their beach, and he anguishes over the loss of Bouboulina. Zaharia comes to them, saying that he has burnt the monastery and is now free of the demon which lived inside of him. He leaves for the beach, and sometime later Zorba goes out to shave his face. He returns to the narrator with the news that Zaharia has died on the beach, his heart seeming to have simply stopped.
The day before May 1st is the great unveiling of the cable railway system. Many villagers are invited, including the abbot. Just before the first tree is to be sent down the mountain, a group of monks run down the path carrying the Most Holy Virgin, as Zorba has tricked them into believing that the Holy Virgin of Revenge has killed Zaharia for burning the monastery. They load the first tree and send it down the mountain, and it sparks and burns up. This happens twice more, and on the fourth trunk, the entire system comes crashing down.
After this spectacular failure, the narrator finally agrees to let Zorba teach him how to dance. He thinks of how happy he is here, with Zorba, even in the wake of this disaster which will surely ruin their chances of making money. The next morning he is exorbitantly happy, and he runs up the mountain to relax. He receives a premonition though, that his great friend Stavridaki has died, and thus runs back down the mountain yelling his name. He realizes it is in vain that he is panicking, and so he calms down and realizes he is hungry and tired.
Their whole venture now over, it is time for Zorba and the narrator to separate. They are both emotional about this, but both too proud and ashamed to express it. Zorba says they must end their final night together quickly, as his father taught him. In the morning when the narrator wakes up, Zorba is gone. He receives a telegram alerting him of Stavridaki's death, and then he leaves Crete. Over the years he receives various postcards from Zorba, but he never sees him again. In the end, he writes of Zorba's incredible life and the experiences he shared with him. He later receives a letter from the schoolmaster of a German village, informing him that Zorba had died. Zorba asked the schoolmaster to inform the narrator that he had been left Zorba's santuri, one of his most prized possessions.