Winona Ryder – Joyce Byers, the mother of Will and Jonathan.

David Harbour  – Jim Hopper, the sheriff of Hawkins. In the fourth season, he escapes from a camp in the USSR.

Millie Bobby Brown  – Jane Hopper or Eleven (El), the adoptive daughter of Sheriff Hopper. She has psychokinetic and telepathic abilities.

Finn Wolfhard  – Michael Wheeler, Nancy’s brother. One of the main characters of the series and in love with Eleven.

Noah Schnapp – Will Byers, Jonathan’s brother. The events of the first season kick off with his mysterious disappearance.

Gaten Matarazzo – Dustin Henderson, a friend of Mike, Lucas, and Will.

Caleb McLaughlin  – Lucas Sinclair, a friend of Mike, Dustin, and Will. He has a crush on Max.

Natalia Dyer  – Nancy Wheeler, sister of Mike and girlfriend of Jonathan.

Charlie Heaton  – Jonathan Byers, Will’s brother and Nancy’s boyfriend.

Joe Keery – Steve Harrington, Nancy’s ex-boyfriend.

Sadie Sink – Max Mayfield, Eleven’s best friend. She falls into a coma at the end of the fourth season.

Maya Hawke – Robin Buckley, Steve’s friend.