On a late autumn night, a spaceship filled with foliage and fungi sits among the trees of a quiet forest. Small, squat alien creatures wander near the ship observing plants on Earth until their chests illuminate red. One alien wanders off alone, looking at the city lights below, when a brigade of trucks parks nearby and humans begin to inspect the area with flashlights. The extra-terrestrial’s chest glows red, attracting the attention of the humans, and the creature runs screeching back toward its spaceship. However, the aircraft’s ramp closes and the ship launches into the sky, leaving the alien behind. Meanwhile, as a group of boys play games in a suburban home, Michael instructs his younger brother, Elliott, to retrieve pizzas from the deliveryman. While outside, Elliott hears a rustling in the illuminated shed behind the house. Believing the noise to be coming from the dog, Harvey, the boy tosses a baseball inside the shed, but the ball is thrown back to him. Elliott leads the other boys and his mother, Mary, outside to show them the strange occurrence. There, they find unusual footprints, which they assume were made by coyotes. After everyone has gone to sleep, Elliott inspects the yard and nearby cornfield with a flashlight. He follows a pair of tracks into the dirt and encounters the wrinkly, blue-eyed extra-terrestrial, which screams and runs away. The next morning, Elliott rides his bicycle into the park, dropping a trail of Reese’s Pieces candies behind him, but quickly returns home when he notices a man inspecting the area. During dinner, the boy insists that the alien he saw was real, despite the skepticism from his mother, brother, and younger sister, Gertie. When Elliott mentions that his absent father is in Mexico with a woman named Sally, his mother begins to cry and leaves the room. That night, Elliott sits outside on a lawn chair and the alien approaches him, dropping a handful of Reese’s Pieces at his feet. Elliott uses more of the sweets to lure the creature into his bedroom, where the alien mimics Elliott’s movements and watches the boy as he falls asleep. Elsewhere, a group of men use radar equipment to search the forest and find a cluster of the forgotten candies. The next day, Elliott feigns illness so he can stay home while his mother goes to work and his siblings attend school. The boy speaks to the alien and shows it his belongings. Once he retrieves food from the kitchen, Elliott draws a bath and speaks to his mother on the telephone while the alien swims in the water. After school, Elliott shows the creature to Michael and Gertie, who yell in alarm, but agree to keep the creature a secret from their mother. The alien uses its powers to levitate balls of clay into the air, mimicking the orbit of planets in the solar system, and revive a wilted flower. Although amazed, Elliott becomes concerned about beeping noises and voices of the scientists nearing the house. After Elliott and Michael leave for school, Mary hears shuffling in Elliott’s closet, but the alien hides itself among the children's stuffed animals. While Elliott attends a dissection lesson in biology class, the creature drinks beer from the refrigerator at home. As the alcohol takes effect in the alien’s body, their telepathic connection causes Elliott to simultaneously become intoxicated and slide out of his chair. Meanwhile, the alien reads a newspaper comic depicting spacemen attempting to contact their home planet, and watches television programs featuring flying spaceships and people using telephones. In class, Elliott frees the frogs from their jars before their classmates can dissect them. As the alien watches John Wayne kiss Maureen O’Hara in The Quiet Man, Elliott grabs his classmate and kisses her, prompting a teacher to drag him away. The alien then dismantles a Speak & Spell toy and carries various household items upstairs to the closet. Later, Gertie attempts to show the creature to her mother, but Mary is distracted putting away groceries and does not notice that it has begun to mimic the girl's educational television program. She then receives a telephone call from the school and leaves to pick up Elliott. When the boy returns home, he finds that Gertie has dressed the alien in a dress and wig, and that the creature can now speak. Elliott calls the creature “E.T.,” and E.T. uses signals and its limited vocabulary to tell the children that it wishes to “phone home.” That night, a man drives by the house in a van and eavesdrops on Elliott and Michael rummaging through the garage for equipment to build a radar machine. On Halloween, Elliott reminds Gertie to meet him at “the lookout” point later that evening, and covers E.T. in a sheet, pretending it is his sister dressed as a ghost. He and Michael lead E.T. up the hill to meet Gertie with his bicycle, and Elliott rides into the woods with E.T. in the front basket. After nightfall, E.T. levitates the bike into the air and they ride through the sky. Elliott then helps E.T. construct a device that will send a signal to the alien's home planet. When the children do not return home that night, Mary leaves to search for them, and a group of suited men enter the house. She finds Gertie and Michael on the streets, who inform her that Elliott is in the forest. Meanwhile, the wind pushes the gears on the machine, emitting a code out into space. Upset by the thought of E.T. leaving, Elliott cries and falls asleep among the trees. The next morning, Mary reports Elliott’s disappearance to a police officer, but the boy returns home, ill and alone. Michael finds E.T., white and sickly, lying in a stream. When he brings the dying creature home and shows it to Mary, she attempts to take the children away. However, a team of scientists dressed in spacesuits enter the house and cover the premises in protective quarantine barriers. While scientists run medical tests on E.T. and Elliott and asks the family questions, Michael informs them that his brother is able to telepathically sense E.T.’s feelings, and one man tells Elliott he is glad that he found E.T. before they did. As Elliott regains strength through the night, E.T. fades, and the alien’s heart eventually stops. Despite the scientists’ efforts to resuscitate the creature, E.T. dies, and they pack its body in a nitrogen chamber. As Elliott says goodbye, E.T.’s chest glows red, and a nearby pot of wilting flowers blooms again. E.T. repeats “E.T. phone home,” prompting Elliott to realize that the alien’s companions are returning. Elliott loudly weeps to distract the doctors from noticing that E.T. is still alive, and later Mike steals a medical van, with Elliott and E.T. hiding in back. He instructs his friends to meet them at the top of the hill as Mary and Gertie chase after them in the car, the scientists trailing behind. The boys ride their bicycles through the neighborhood with E.T. perched in Elliott’s basket, lifting them into the air to evade the police. As they reach the forest, E.T.’s spaceship lands in the clearing, and Mary arrives with Gertie. The girl gives E.T. a flower pot, and the alien tells her to “be good.” Elliott asks his friend to stay, but E.T. hugs the boy goodbye, assuring him, “I’ll be right here,” before walking up the ramp. The spaceship flies away, leaving behind a rainbow in the sky.