Tarzan is the son of a British lord and lady who were marooned on the Atlantic coast of Africa by mutineers. When Tarzan was an infant, his mother died, and his father was killed by Kerchak, leader of the ape tribe by whom Tarzan was adopted. Soon after his parents' death, Tarzan became a feral child, and his tribe of apes are known as the Mangani, Great Apes of a species unknown to science. Kala is his ape mother. Burroughs added stories occurring during Tarzan's adolescence in his sixth Tarzan book, Jungle Tales of Tarzan. Tarzan is his ape name (meaning "White-Skin"); his English name is John Clayton, Viscount Greystoke (according to Burroughs in Tarzan, Lord of the Jungle; Earl of Greystoke in later, less canonical sources, notably the 1984 movie Greystoke). In fact, Burroughs's narrator in Tarzan of the Apes describes both Clayton and Greystoke as fictitious names – implying that, within the fictional world that Tarzan inhabits, he may have a different real name.

In his book Tarzan: The Biography, author Sean Egan argues that the name "Tarzan" is illogical, asserting that it is "a non-guttural word not the sort of sound that naturally emanates from the mouth of even a man-like simian." He also says filmmakers down the decades have consistently failed to acknowledge the incongruity of Tarzan’s name, with a few exceptions, such as the 1998 movie Tarzan and the Lost City and the 2017 Netflix series Tarzan and Jane, which came up with a logical get-around by making the name one bequeathed by Africans, and Greystoke, which dispensed with the problem by jettisoning the name entirely.

As an eighteen-year-old young adult, Tarzan meets a young American woman, Jane Porter. She, her father, and others of their party are marooned on the same coastal jungle area where Tarzan's biological parents were twenty years earlier. When Jane returns to the United States, Tarzan leaves the jungle in search of her, his one true love. In The Return of Tarzan, Tarzan and Jane marry. In later books he lives with her for a time in England. They have one son, Jack, who takes the ape name Korak ("the Killer"). Tarzan is contemptuous of what he sees as the hypocrisy of civilization, and he and Jane return to Africa, making their home on an extensive estate that becomes a base for Tarzan's later adventures.

As revealed in Tarzan's Quest, Tarzan, Jane, Tarzan's monkey friend Nkima, and their allies gained some of the Kavuru's pills that grant immortality to its consumer.

Burroughs created an elegant version of the wild man figure largely unalloyed with character flaws or faults. Tarzan is described as being tall, athletic, handsome, and tanned, with grey eyes and long black hair. He wears almost no clothes, except for a loincloth. Emotionally, he is courageous, intelligent, loyal, and steadfast. He is presented as behaving ethically in most situations, except when seeking vengeance under the motivation of grief, as when his ape mother Kala is killed in Tarzan of the Apes, or when he believes Jane has been murdered in Tarzan the Untamed. He is deeply in love with his wife and totally devoted to her; in numerous situations where other women express their attraction to him, Tarzan politely but firmly declines their attentions. When presented with a situation where a weaker individual or party is being preyed upon by a stronger foe, Tarzan invariably takes the side of the weaker party. In dealing with other men, Tarzan is firm and forceful. With male friends, he is reserved but deeply loyal and generous. As a host, he is, likewise, generous and gracious. As a leader, he commands devoted loyalty.

In keeping with these noble characteristics, Tarzan's philosophy embraces an extreme form of "return to nature". Although he is able to pass within society as a civilized individual, he prefers to "strip off the thin veneer of civilization", as Burroughs often puts it. His preferred dress is a knife and a loincloth of animal hide, his preferred abode is any convenient tree branch when he desires to sleep, and his favored food is raw meat, killed by himself; even better if he is able to bury it a week so that putrefaction has had a chance to tenderize it a bit.

Tarzan's primitivist philosophy was absorbed by countless fans, amongst whom was Jane Goodall, who describes the Tarzan series as having a major influence on her childhood. She states that she felt she would be a much better spouse for Tarzan than his fictional wife, Jane, and that when she first began to live among and study the chimpanzees she was fulfilling her childhood dream of living among the great apes just as Tarzan did.

Rudyard Kipling's Mowgli has been cited as a major influence on Edgar Rice Burroughs' creation of Tarzan. Mowgli was also an influence for a number of other "wild boy" characters.

Tarzan's jungle upbringing gives him abilities far beyond those of ordinary humans. These include climbing, clinging, and leaping as well as any great ape, or better. He uses branches and hanging vines to swing at great speed, a skill acquired among the anthropoid apes.

His strength, speed, stamina, agility, reflexes, senses, flexibility, durability, endurance, and swimming are extraordinary in comparison to normal men. He has wrestled full grown bull apes and gorillas, lions, rhinos, crocodiles, pythons, sharks, tigers, man-size seahorses (once) and even dinosaurs (when he visited Pellucidar). Tarzan is a skilled tracker and uses his exceptional senses of hearing and smell to follow prey or avoid predators, and kills only for food, yet is a skilled thief when raiding African tribal villages or hunting parties that Tarzan has judged to be brutal and deserve no pity, taking their spears, shields, bows, knives, and most importantly, metal arrowheads. A keen sense of hearing allows him to eavesdrop on conversations between other people near him.

Extremely intelligent, Tarzan was literate in English before being able to speak the language when he first encounters other English-speaking people such as his love interest, Jane Porter. His literacy is self-taught after several years in his early teens by visiting the log cabin of his dead parents and looking at and correctly deducing the function of children's primer/picture books. The books were brought to Africa by his dead mother who intended to teach her son herself. He eventually reads every book in his dead father's portable book collection and is fully aware of geography, basic world history, and his family tree, yet is not able to speak English until after meeting human beings as he never heard what English is supposed to sound like when spoken aloud. He is "found" by a traveling Frenchman that teaches him the basics of human speech and returns him to England.

Tarzan can learn a new language in days, ultimately speaking many languages, including that of the great apes, French, Finnish, English, Dutch, German, Swahili, many Bantu dialects, Arabic, ancient Greek, ancient Latin, Mayan, the languages of the Ant Men and of Pellucidar.

Unlike depictions in black and white movies of the 1930s after learning to speak a language in the novels, Tarzan/John Clayton is very articulate, reserved (he prefers to listen and carefully observe before speaking) and does not speak in broken English as the classic movies depict him.

He can communicate with many species of jungle animals, and has been shown to be a skilled impressionist, able to mimic the sound of a gunshot perfectly.

The Kavuru's pills later granted Tarzan extended longevity.

Tarzan has been called one of the best-known literary characters in the world. In addition to more than two dozen books by Burroughs and a handful more by authors with the blessing of Burroughs' estate, the character has appeared in films, radio, television, comic strips, and comic books. Numerous parodies and pirated works have also appeared.

Burroughs considered other names for the character, including "Zantar" and "Tublat Zan," before he settled on "Tarzan."

Even though the copyright on Tarzan of the Apes has expired in the United States of America and other countries, the name Tarzan is claimed as a trademark of Edgar Rice Burroughs, Inc.

It's also worth noting that Burroughs use of dates and time passing is constantly inconsistent in his novels, in fact there are downright contradictions in the series. In the first book Tarzan Of The Apes it's implied that Tarzan was born early in 1888 and the arrival of Jane is said to have occurred in 1909 which would make him 20 years old. In Tarzan Of The Apes, chapter 9, Burroughs states:

Thus, at eighteen, we find him, an English lordling, who could speak no English, and yet who could read and write his native language. Never had he seen a human being other than himself, for the little area traversed by his tribe was watered by no great river to bring down the savage natives of the interior.

Two paragraphs later Mbonga's warriors enter. Yet in The Return Of Tarzan, chapter 5, when the ape man almost killed the Count de Coude Tarzan states:

Until I was fifteen I