The Jungle Boy is an unnamed youth who lives in the jungle on the island. He can talk, but he can only repeat the last few words of people around him. According to Gilligan, the boy swings like a monkey, swims like a fish and runs like a deer, making him very hard to catch. The youth first makes contact with Gilligan and shows him the natural gas mines on the island. He soon meets the other Castaways and observes them building a hot-air balloon utilizing the natural gas. However, he soon uses the balloon himself to leave the island, later ending up on an aircraft carrier without the means to tell anyone about the castaways.
- Jungle Boy was played by actor Kurt Russell, best known for several Disney movies during the Seventies.
- The Jungle Boy may have been inspired from Mowgli from Rudyard Kipling's 1894 classic The Jungle Book, an Indian feral child who was raised by a panther named Bagheera, and Tarzan from Edgar Rice Burrough's Tarzan of the Apes series.