Who is Dewey in Malcolm in the Middle?

Show

Malcolm in the Middle

Played by

Erik Per Sullivan

First episode

“Pilot”Season 1, Episode 1, aired January 9, 2000

Role

Main cast

Network

FOX

Occupation

Kid, musical prodigy

Show run

2000 to 2006

Dewey starts out as the strange little brother everyone underestimates, and he spends the series proving them wrong. Played by Erik Per Sullivan, he is innocent, eerie, and surprisingly ruthless when someone finally pushes him too far.

On Malcolm in the Middle, Dewey's story runs through Malcolm (Older Brother), Reese (Older Brother), Francis (Oldest Brother), Lois (Mother), and Hal (Father).

Who is Dewey?

Dewey is Hal and Lois's fourth son and the baby of the family until Jamie arrives in season four. In the early seasons he is mostly a target: Malcolm and Reese prank him, scare him, and pin the blame on him, and he wanders through the chaos with a calm, slightly off-kilter view of the world.

As he gets older, the show reveals that Dewey is extremely bright, more drawn to the arts than his brothers, and capable of elaborate revenge. He also becomes the family's quiet conscience, refusing to bully Jamie the way he was bullied.

Personality and comedy

Dewey's humor is deadpan and a little uncanny. Years of abuse from his brothers have given him an almost superhuman tolerance for pain and humiliation, and he often wins simply by outlasting everyone. When he does strike back, it is with patient, Machiavellian schemes that leave Malcolm and Reese at his mercy.

Erik Per Sullivan plays him with a wide-eyed stillness that makes even his oddest choices feel sincere. Dewey's growing resentment that his parents have overlooked him and his interests adds a bittersweet edge to the later seasons.

Key storylines

Dewey teaches himself piano and turns out to be a musical prodigy, eventually writing an entire opera based on his parents' arguments that is staged at his school. In season five, a botched IQ test lands him in the class for emotionally troubled kids, known as the Buseys. Dewey becomes their unofficial teacher and cares about them so much that he fakes emotional problems to stay when the mistake comes to light.

In the final seasons he insists that Jamie get the attention he never had, and in "Morp" he punishes his parents for the missing photos of his childhood with an elaborate scavenger hunt. The series finale's epilogue shows Dewey and Jamie, the last brothers living at home, carrying on the family tradition of wrecking the house.

Behind the scenes and legacy

Erik Per Sullivan played Dewey for the full original run from 2000 to 2006. He did not return for the 2026 revival, Malcolm in the Middle: Life's Still Unfair, in which adult Dewey is played by Caleb Ellsworth-Clark, while Sullivan appears only in archival flashback footage.

In the revival, adult Dewey is a successful musician who spends much of his time touring the world and appears mostly by video call, a fitting payoff for the kid whose talent the family kept missing.

Dewey: frequently asked questions

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