In the late 1880s, a British couple and their infant son are shipwrecked off the coast of West Africa. They build a treehouse in the jungle, but are soon killed by Sabor, a fierce leopard. A female gorilla named Kala, who has recently lost her own child to the same predator, hears the baby's cries and rescues him. Despite the disapproval of Kerchak, the troop's powerful silverback leader, Kala raises the boy as her own, naming him Tarzan.

As Tarzan grows, he struggles to fit in due to his physical differences from his gorilla family. He develops unique skills to compensate, fashioning tools and a spear, and forms deep friendships with the clumsy elephant Tantor and the sarcastic gorilla Terk. Determined to prove himself, Tarzan eventually confronts and kills Sabor, finally earning Kerchak's respect.

Years later, a human expedition arrives, led by the hunter Clayton and consisting of Professor Archimedes Q. Porter and his spirited daughter, Jane. When Jane is separated from the group and chased by a troop of baboons, Tarzan rescues her. Fascinated by Jane, who is the first human he has ever seen, Tarzan visits the camp to learn about her world, quickly picking up language and customs. He and Jane develop a deep bond.

Clayton, however, is not a true scientist. He is a greedy poacher who wants to capture the gorillas and sell them. He manipulates Tarzan into leading the group to the gorilla nesting grounds by promising that Jane will stay. When Kerchak finds the humans, he attacks, driving them away and banishing Tarzan for betraying the troop. Heartbroken, Tarzan learns from Kala of the treehouse where he was found, finally understanding he is human but that she chose to love him as her son.

Tarzan decides to leave with Jane for England, but discovers Clayton and his crew capturing the gorillas. He escapes the ship and returns to the jungle to fight back. In the ensuing battle, Kerchak is mortally wounded while saving Tarzan from a gunshot. In a final confrontation among the trees, Clayton accidentally hangs himself in a tangle of vines while trying to shoot Tarzan.

With his dying breath, Kerchak acknowledges Tarzan as his son and names him the new leader of the gorilla troop. The captured apes are freed, and Clayton's men are driven away. Although Professor Porter and Jane prepare to depart, Jane chooses to stay in the jungle with Tarzan, who has found his true home and purpose as the protector of his family.