Holly Wheeler is portrayed as being around 9–10 years old in the latest Stranger Things season, even though the in‑universe timeline would technically make her closer to 7.

On-screen age

Multiple guides to the final season state that Holly and her classmates are described as being “between nine and ten years old” in an episode set at school. These sources also summarize her as “around 10 years old” during the events of the show’s final season.

Timeline vs. stated age

Within the story’s timeline, Holly is introduced as a three‑year‑old in season 1, which is set in November 1983, and season 5 is set in November 1987, so by strict chronology she would be about seven. Commentaries note that the show effectively ages her up a bit so she can play a more active role, leading most references to list her as roughly 9–10 years old in the new season.