The first season of “Stranger Things” has 8 episodes. Netflix released the entire season worldwide on July 15, 2016, making all eight chapters available for streaming at once.
The season begins with the disappearance of Will Byers in the fictional Indiana town of Hawkins. His friends Mike, Dustin, and Lucas encounter Eleven, a mysterious girl with supernatural abilities, while Joyce Byers and police chief Jim Hopper investigate Will's disappearance and the secrets of Hawkins National Laboratory.
The episodes use chapter-style titles, including “The Vanishing of Will Byers,” “The Flea and the Acrobat,” “The Bathtub,” and “The Upside Down.” The season's eight-episode structure helped establish the show's fast-moving, serialized format, with each chapter advancing both the mystery and the characters' relationships.
The number is sometimes confused with later seasons, which have different episode counts. Season 2 has nine episodes, while Season 3 has eight and Season 4 has nine, so the first season's answer is specifically eight.