Job Anderson: Job Anderson is the boatswain on the Hispaniola. He is one the mutineers, and is killed by Gray in the assault on the stockade.

Billy Bones: Billy Bones is the old seaman who stays at the Admiral Benbow inn, where he is known as the captain. He is a pirate who has acquired the map that shows where Captain Flint buried the treasure. Flint's former associates therefore search for him, and when they find him and serve him his death warrant, he has a fit and dies. 

Black Dog: Black Dog is a pirate who tracks down Billy Bones at the Admiral Benbow inn. The two men fight, and Black Dog escapes.

Abraham Gray: Abraham Gray is a carpenter's mate who joins the crew of the Hispaniola. After some wavering, he decides not to join the mutineers, and he plays his part in their defeat.

Ben Gunn: Ben Gunn is a pirate and former member of Captain Flint's crew who has been  marooned alone on Treasure Island for three years. He joins forces with Jim and his party and helps them defeat the mutineers.

Israel Hands: Israel Hands is the coxswain of the Hispaniola. He is one of the mutineers, and he tries to kill Jim Hawkins, but Jim kills him instead.

Jim Hawkins: Jim Hawkins is the principal narrator of the story. He gets involved in the adventure because his parents own the Admiral Benbow inn where Billy Bones comes to stay. Jim is a young boy who is forced by events to mature very quickly. After his father's death he begins to make his own way in the world. He is cabin boy on the Hispaniola, and through his initiative, impulsiveness, curiosity and daring, he plays a crucial role in the eventual defeat of the pirates: he retrieves the map of Treasure Island from Billy Bones; he becomes aware of Silver's plot and informs the ship's officers; and he meets Ben Gunn, which leads him to Ben's boat, which enables him to reboard and recapture the Hispaniola, killing Israel Hands in self-defense. Many times Jim is in danger of his life, but he survives.

John Hunter: John Hunter is one of Squire Trelawney's men. He is killed when the pirates attack the stockade on Treasure Island.

Richard Joyce: Richard Joyce is one of Squire Trelawney's men. He is killed by the pirates as they attack the stockade on Treasure Island.

Dr. Livesey: Dr. Livesey is the family physician who treats Jim Hawkins's dying father and also attends to Billy Bones. As the ship's doctor, he treats the wounded pirates, even though they are his enemies. Dr. Livesey is no stranger to violence, having in the past served the Duke of Cumberland and been wounded in battle.

Morgan: Morgan is one of the mutineers. At one point he is ready to kill Jim but Silver intervenes and prevents him. 

Pew: Pew is the blind pirate who comes looking for Billy Bones and delivers him the Black Spot. After Bones's sudden death, Pew leads a group of pirates to retrieve the treasure map. He is trampled to death by the horses of revenue officers who come to the rescue.  

Redruth: Redruth is Squire Trelawney's gamekeeper. He sails on the Hispaniola, but is shot and killed by mutineers as he and the other crew members go ashore for the first time.

Long John Silver: Long John Silver is a one-legged pirate who was quartermaster to the notorious Captain Flint. He is a very cunning, amoral man who puts on a friendly, helpful exterior while all the time planning treachery. Initially, the squire and Jim like Silver, and as he performs his duties as cook on the Hispaniola, he appears to be a model member of the crew. However, he soon reveals his ruthless, violent side, and once the buccaneers are on the island he murders one of the crew, as Jim watches. After this, Silver uses all his cunning to make sure that he emerges on the winning side, whichever that might be. However, Silver does have some redeeming qualities. He has a genuine affection for Jim Hawkins, and his independent spirit and resourcefulness often compel admiration.

Captain Smollett: Captain Smollett is the captain of the Hispaniola. At the beginning of the voyage he makes his misgivings known to Trelawney, who dislikes him. But Smollett is soon proved correct  in his judgments and Trelawney is forced to change his opinion. As a captain, Smollett excels in his tasks, and when the mutiny begins he is determined and resolute. He frequently takes charge of the situation and efficiently marshals the men for the defense of the loghouse. After he is wounded, however, he takes no further part in the action.

Squire Trelawney: Squire Trelawney is excited by the prospect of finding treasure and he finances the entire expedition. He buys the Hispaniola and selects a crew, but he cannot keep a secret and everyone seems to get to know about the nature of the mission. The squire is a well-traveled man and the best shot amongst the crew. He also shows effective leadership qualities and keeps a cool head throughout the adventure.