Adam is a young boy who ends up becoming one of the Flayed. Adam is summoned by the Mind Flayer during the 4th of July celebration, where his friend calls to him saying he's going to miss the fireworks. Unfortunately, Adam is killed and melted by the Mind Flayer to form his proxy body.
Anna Jacobi was a high school graduate who frequently visited the Starcourt Mall. Steve tried to ask her out in a game he played with Robin. Later, Steve got angry when he saw her talking to Mike Lewenski.
Candice is Mayor Kline's secretary. Candice and Kline are having an affair which Chief Hopper is aware of. When Hopper threatens Kline to inform him about his relationship with Grigori, Candice becomes concerned for Kline but is stopped by Joyce Byers from calling security.
David is one of the few victims to become one of the Flayed. During the 4th of July celebration, David is summoned by the Mind Flayer, as he was barbecuing food. His wife asks him where he's going, but he leaves the food to be burnt by the barbecue as he's summoned by the Mind Flayer. Once he arrives at the source, Brimborn Steel Works, the Mind Flayer kills and melts David, using his remains to finish his proxy body.
Dr. Zharkov is a Russian doctor working for Commander Ozerov, who specializes in torturing hostages. Dr. Zharkov injected Steve and Robin with truth serum and nearly ripped out Steve's fingernail until Robin confessed how they found the Russian base. Before Ozerov and Zharkov could do any more harm to their hostages, an alarm system went off, leading Ozerov to investigate. Once he was gone, Dustin Henderson and Erica Sinclair burst into the room, with Dustin killing Dr. Zharkov with a taser, saving Steve and Robin. Dr. Zharkov is portrayed by Arthur Darbinyan.
Jill was one of Karen Wheeler's friends that visited the Hawkins Community Pool on a daily basis to flirt with Billy. During one visit, Karen asked Jill to watch Holly for her so she could talk to Billy in secret.
Liz was one of Karen Wheeler's friends that accompanied her to the Hawkins Community Pool on a daily basis to flirt with Billy.
Mike Lewenski was a high school graduate in Steve's grade. Steve described him as "a meathead who never even came off the bench."
Ricky was a cashier that worked at a 7-Eleven located in an unknown town in Indiana. On their journey to Murray Bauman's residence, Hopper, Joyce, and Alexei stumbled upon the convenience store. While they were stocking up on supplies, Ricky inquired if they were going to pay for their items. Sometime later, Grigori entered the same store and forced Ricky to disclose any information he had regarding the trio. Ricky is portrayed by Michael Silvio Fortino.
Todd was a customer at a 7-Eleven as he filling his car's gas tank. However, the Police Chief of Hawkins, Jim Hopper decided to take to Todd's car in order to get to Murray's warehouse in a faster way. Hopper convinces Todd that he needed his car in order to get Alexei saying he's a murder, which makes Todd give his car keys to Hopper. However, when Joyce Byers says he's a forger, Todd becomes unconvinced and watches as the trio drive off in his car. Later, when Grigori arrived at the 7-Eleven, he noticed Todd talking to the police.
Unnamed Government Man
An unnamed government man was working at the 'Philadelphia Public Library' as an agent of Dr. Sam Owens. He was contacted by Hopper and Joyce to inform Owens to bring back-up to prevent the Russians' attempt in opening the Gate at Starcourt Mall.
Unnamed Pool Manager
An unnamed pool manager was the head of the Hawkins Community Pool. He chatted sassily with El and Max while they were searching for Heather.
Unnamed Russian Scientist
An unnamed Russian scientist was one of the two scientists, along with Alexei to build and operate a Key in Russia in 1984. However, when the Key failed to open a portal to the Upside Down, the scientist was coldly executed by Grigori, on Stepanov's orders as Alexei watched.
Unnamed Hospital Receptionist
An unnamed woman was working as a hospital receptionist at Hawkins Memorial Hospital. She would only allow family members and two visitors at a time to visit those they're close to at the hospital. When she's not approached by anyone, she spends her time talking and gossiping over the phone.
Winnie Kline is the wife of Mayor Larry Kline. She's unaware of her husband's affair with his secretary and possibly his shady dealings with the Russians working in Starcourt Mall. Despite this, Winnie is shown to care for her husband when she finds him handcuffed to the bed by Chief Hopper.
Unseen or Mentioned
Jack Driscoll is the late husband of Doris Driscoll. According to Doris, he died in 1975.
Tammy Thompson was a classmate of Steve Harrington and Robin Buckley in Hawkins High School. Robin had a crush on her, but Tammy was attracted to Steve, making Robin jealous. According to Steve, Tammy wants to be a singer and go to Nashville, Tennessee.
Tina is a friend of Erica Sinclair. Erica mentioned to be at Tina's for a sleepover, but says that Tina always covers for Erica when she is not around, to which Steve replies he doesn't care about Tina.
Wendy was a friend of Billy's mother.