Dustin Henderson is 12 years old in Season 1 of Stranger Things.

Quick answer

In the show’s timeline, Season 1 is set in November 1983, and Dustin—along with the rest of the core kids (Mike, Lucas, Will, and Eleven)—is written as being about 12 years old. Behind the scenes, Gaten Matarazzo, who plays Dustin, was 13 when he filmed Season 1, so the character is slightly younger than the actor.

Dustin’s age in Season 1

  • Multiple cast-age breakdowns list Dustin as 12 in Season 1 while confirming Gaten Matarazzo was 13 during filming.
  • Fan Q&A and forum discussions consistently repeat the pairing “Dustin: character 12, actor 13,” aligning with the show’s middle-school setting.

How this fits the show timeline

  • Season 1’s events in Hawkins take place in late 1983, when the boys are in middle school, just before they later transition into high school in later seasons.
  • Other main kids like Mike, Will, Lucas, Max, and Eleven are also placed around 12 in Season 1, keeping the core friend group in the same school-year bracket.

Extra context for fans

  • Articles tracking the cast “then vs now” show how much Gaten has aged from a 13-year-old filming Season 1 to his early 20s by the time of the later seasons.
  • Discussions on fan forums often note that using slightly older teen actors to play 12-year-olds helps with performance and production demands, which is common in TV and film.

TL;DR: Dustin is about 12 years old in Stranger Things Season 1, while Gaten Matarazzo was 13 when he played him.

Information gathered from public forums or data available on the internet and portrayed here.