* Beverly Marsh, played by Sophia Lillis (young) and Jessica Chastain (adult)
* Ben Hanscom, played by Jeremy Ray Taylor (young) and Jay Ryan (adult)
* Eddie Kaspbrak, played by Jack Dylan Grazer (young) and James Ransone (adult)
* Mike Hanlon, played by Chosen Jacobs (young) and Isaiah Mustafa (adult)
* Richie Tozier, played by Finn Wolfhard (young) and Bill Hader (adult)
* Stanley Uris, played by Wyatt Oleff (young) and Andy Bean (adult)