Cast & creator
Jeff 'Swampy' Marsh
Best known for Phineas and Ferb, Phineas and Ferb, Phineas and Ferb
Jeff "Swampy" Marsh (born December 9, 1960) is an American animator, writer, director, producer, and voice actor associated with several animated television series, most notably as an executive producer and the voice of Major Monogram for Disney's animated series Phineas and Ferb and Milo Murphy's Law, both of which he co-created with Dan Povenmire. Marsh was born in Santa Monica, California, where he grew up with a heavily blended family dynamic. Marsh has been and continues to be a driving force behind several animation projects, working for over six seasons on the animated television series The Simpsons. Marsh continued to work on other animated television series, including King of the Hill and Rocko's Modern Life, before moving to England in 1996.
Also known as: Jeff "Swampy" Marsh , Jeff Harsh, Jeff Swampy Marsh, Jeffrey Marsh, Jeff Marsh
19
film credits
25
television credits
16
1993–2026 · acting roles
7.3
average across scored titles
Signature credits
Known for
Across film & television
Filmography (44)
Showing 44 of 44 credits
Phineas and Ferb
Francis Monogram (voice)
2007Phineas and Ferb
Director
2007Phineas and Ferb
Executive Producer
2007Phineas and Ferb
Writer
2007Phineas and Ferb
Story
2007Phineas and Ferb
Creator
2007
Milo Murphy's Law
Additional Voices (voice)
2016Milo Murphy's Law
Executive Producer
2016Milo Murphy's Law
Story
2016Milo Murphy's Law
Creator
2016
Rocko's Modern Life
Storyboard Artist
1993Rocko's Modern Life
Director
1993Rocko's Modern Life
Additional Writing
1993
Pete the Cat
Writer
2017Pete the Cat
Creator
2017
Take Two with Phineas and Ferb
Executive Producer
2010Take Two with Phineas and Ferb
Creator
2010
Phineas and Ferb the Movie: Across the 2nd Dimension
Major Francis Monogram / Monogram-2 (voice)
2011Phineas and Ferb the Movie: Across the 2nd Dimension
Sequence Supervisor
2011Phineas and Ferb the Movie: Across the 2nd Dimension
Executive Producer
2011Phineas and Ferb the Movie: Across the 2nd Dimension
Writer
2011
How Not to Draw
Major Monogram (voice)
2022
Phineas and Ferb the Movie: Candace Against the Universe
Major Monogram (voice)
2020Phineas and Ferb the Movie: Candace Against the Universe
Executive Producer
2020Phineas and Ferb the Movie: Candace Against the Universe
Writer
2020
Aaagh! It's the Mr. Hell Show!
Josh (voice)
2001
Super Happy Magic Forest
Executive Producer
2024
Agent P Under C
Major Monogram (voice)
2026
Phineas and Ferb: Mission Marvel
Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
2013
Phineas and Ferb: Star Wars
Major Hologram / Imperial Officer Jeff / Additional Voices
2014
Shadow of the Elves
Director
2004
Cartoonified! With Phineas and Ferb
Creator
2025
I Know That Voice
Self
2014
Spiked
Big Boss Croc / Exterminator (voice)
2025
Hey A.J.!
Executive Producer
2026
Bounty Hamster
(voice)
2003
Phineas and Ferb: The Daze of Summer
2012Phineas and Ferb: The Daze of Summer
Writer
2012
TV's Funniest Animated Stars: A Paley Center for Media Special
Self
2015
Untitled Phineas and Ferb Movie
Major Francis Monogram (voice)
Untitled Phineas and Ferb Movie
Writer
Untitled Phineas and Ferb Movie
Executive Producer
Phineas and Ferb: The Perry Files - Animal Agents
Major Monogram (voice)
2013
Looks Can Kill
Associate Producer
1994