An alien is left behind on Earth and is saved by young Elliot (Henry Thomas) who decides to keep him hidden. While the task force hunts for it, Elliot and his siblings form an emotional bond with their new friend.

Bringing the extraterrestrial into his suburban California house, Elliott introduces E.T., as the alien is dubbed, to his brother and his little sister, Gertie (Drew Barrymore), and the children decide to keep its existence a secret. Soon, however, E.T. falls ill, resulting in government intervention and a dire situation for both Elliott and the alien.