Millie Bobby Brown played the role of Eleven / Jane Hopper. A young girl with telepathic and psychokinetic abilities and a limited vocabulary.
Gaten Matarazzo played the role of Dustin Henderson. The wisecracking friend in the group, Dustin has an outsized personality and confidence to spare.
Natalia Dyer played the role of Nancy Wheeler. Nancy is Mike's older sister and, at the beginning of the show, Steve's girlfriend.
Charlie Heaton played the role of Jonathan Byers. A loner, Jonathan keeps to himself but enjoys photography. He develops a bond with Nancy as they search for his brother and Barb.
David Harbour played the role of Jim Hopper. Chief of Hawkins Police Department. After his young daughter Sara died of cancer, Hopper divorced and lapsed into alcoholism.
Sadie Sink played the role of Max Mayfield. Billy's younger stepsister, and a tomboy catches the attention of both Lucas and Dustin, eventually choosing Lucas.