A young boy named Elliott lives with his single mother, older brother, and little sister in a California suburb. One evening, Elliott encounters a lost alien, stranded on Earth after being left behind by its spaceship. This creature, whom Elliott names "E.T.", is gentle and intelligent, with the power to heal and manipulate objects with its mind. Sensing a kindred spirit in the lonely boy, E.T. forms a special bond with Elliott, who decides to keep his new friend a secret from his family for the time being. As Elliott introduces E.T. to the wonders of Earth and his favorite things, like candy and television, they communicate through a makeshift device E.T. assembles to attempt contact with his home planet.

However, as E.T.'s health begins to decline in the foreign environment of Earth, and the government starts closing in on the suburban neighborhood following reports of a mysterious creature, Elliott and his siblings face the increasing urgency to help E.T. return home. The children, recognizing the deep friendship they've forged with E.T., become determined to protect the alien at all costs. They devise a plan to evade the authorities and bring E.T. to a rendezvous point where he might be retrieved by his fellow extraterrestrials. Fueled by childhood loyalty and the universal desire for belonging, their adventure becomes a race against time to save their friend.