Jackson Stewart is written as a 16‑year‑old in early Hannah Montana, while actor Jason Earles was about 28–29 when filming started.

How Old Was Jackson in Hannah Montana?

On‑screen age vs real age

  • In the show’s early seasons, Jackson is portrayed as a 16‑year‑old teen, a couple of years older than Miley.
  • The in‑universe bio lists Jackson Stewart’s birthdate as May 19, 1983, which fits him being mid‑teens when the series begins.
  • By around season four, fans and commentators generally peg Jackson at about 20 years old in the storyline.

Meanwhile, Jason Earles (who played Jackson):

  • Was born April 26, 1977.
  • Filmed season one starting in late 2005, making him about 28–29 years old while playing a 16‑year‑old.
  • Continued on the show into his early thirties, reaching about 33–34 by the time filming ended.

Fun behind‑the‑scenes twist

Jason Earles has said he actually lied about his age in auditions, telling Disney he was 18 so he could be cast as teen Jackson.

Network execs only found out he was 28 partway through the first season, by which point viewers had already accepted him as Miley’s goofy older brother.

So if you’re wondering “how old was Jackson in Hannah Montana?”:

  • Character: about 16 at the start, around 20 by the end.
  • Actor: late 20s at the start, early 30s by the end.

TL;DR: Jackson was written as a mid‑teen (about 16, later ~20), but Jason Earles was nearly 30 playing him, which fans still love to joke about today.

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