A Cuban fisherman believes his long dry spell will end when he catches a legendary fish.

In Cuba, the old man Santiago has not caught a fish in eighty-four days, making him the object of scorn and pity of the other fishermen. Manolin, the boy who Santiago taught to fish, has been ordered by his parents not to accompany him in his skiff, because they fear the old man is bad luck. Although he dutifully obeys his parents' wishes, the loyal Manolin continues to help Santiago carry his heavy equipment between the boat and his shack. Manolin, who seems old for his age, loves the old man and provides him with coffee in the morning and food in the evening, partly from the money he earns working on another boat and partly begged from the generous café owner, Martin. Often, Santiago will discuss baseball with Manolin, especially the team called the Yankees and the player, Joe Di Maggio, whom he reads about in the newspaper. During the nights, Santiago often dreams about Africa and lion cubs playing on the shore, images he remembers from his youth. In the mornings, Santiago, who is always up early, walks to Manolin's house, where he enters and gently shakes the boy's foot to awaken him. On the eighty-fifth day, Santiago and the other fishermen row out to sea and spread out over the waters. Mid-morning, Santiago is pleased to catch a bonita, a small fish that he can use for bait. About mid-day, he finds that a fish has swallowed one of his fishing lines and has begun pulling the boat slowly northwest. Santiago suspects that it is a large fish and allows it to pull the boat for four hours, until he can no longer see land. When another fish tugs at another line, Santiago cuts the line, believing that he is sacrificing the second fish for a larger one that he has yet to see. Beginning to feel pity for the fish, Santiago reflects that no one can help either of them this far out. By increasing tension on the line, Santiago tries to make the fish jump out of the water so that the air sacs in its backbone will fill up and prevent it from swimming deeper, then waits patiently for results. A small bird that lands in his skiff visits Santiago briefly. To maintain his strength, Santiago eats the bonita. As the fishin line digs into his hands, the fish, a large marlin, emerges from the water. Seeing that the fish is longer than his boat, Santiago muses that although it is not as intelligent as a human, it is more noble and able. Late in the day, it begins to rain, but Santiago refuses to acknowledge that he is suffering. His thoughts turn to the Yankees and he wonders about the results of the most recent game. He then recalls a time in a Casablanca tavern, when he arm wrestled with the strongest man working on the docks, a Negro, in a game that lasted for two days and which he won. Just before dark, as his skiff passes a small island, a dolphin is caught on one of his lines and Santiago eats it raw. His "friends," the stars, come out and Santiago begins to consider the marlin is his friend, too. Having been without sleep for almost two days, Santiago rests and dreams of a school of porpoises, then of lions and then, of whales. As the boat moves into an area of clouds, the jerking of his lines awakens him. He struggles with the marlin, his hands bleeding, and wishes that the boy were with him. As the sun rises, the marlin, which has filled its air sacs, circles around the boat. Although he feels faint, and he is experiencing exhaustion, dizziness and seeing spots before his eyes, Santiago realizes that the fish is much bigger than he thought and begins to pull it in. When he harpoons it, he claims, "I have killed this fish who is my friend." An hour after lashing it to the boat and heading homeward, a shark appears, swimming fast. The old man harpoons and kills the shark, but not before the shark has bitten off forty pounds of flesh from the marlin, which leaves a blood trail that will lure other predators. Santiago lashes his knife to an oar and, when other sharks come, stabs at them, but they eat away at the marlin. After they are gone, the old man tells the ravaged marlin, "I went out too far, fish, no good for you or me." Around ten o'clock at night, Santiago sees the lights of the city and feels his body ache. He apologizes to the fish for "going out too far." More sharks come, just as he expected, and he tries to fight them off, knowing he is beaten. When he draws near his beach colony, the wind and currents bring him in. Reaching land before dawn, he finds the shore deserted and leaves the remnants of the big fish lashed to his boat while he walks slowly home, having to stop and rest on the way. The next morning, the wind is blowing too hard for the fishermen to go out. Manolin, after sleeping late, comes to the old man's shack and, seeing the condition of his hands, cries. When Manolin fetches coffee for Santiago, he finds the other fishermen studying the bones tied to Santiago's skiff and Martin claims there has "never been so fine a fish." When Manolin returns to the shack with the coffee, Santiago despairs that "they beat me," but Manolin reminds him that he did catch the marlin and announces that they will now fish together, despite his father's wishes. Santiago refuses, saying that he is not lucky anymore, but Manolin says, "The hell with luck! I will bring the luck with me." They make plans to start again after the winds die down. In the meantime, Manolin prepares to get new equipment for them and tells the old man to heal. At the café, a party of tourists from Havana see the backbone of the fish, which has been reduced to garbage that will go out with the tide, and think it is a shark. In his shack, the old man sleeps, dreaming about the lions, as the boy watches.