JEFF 'SWAMPY' MARSH

Jeff 'Swampy' Marsh
Jeff 'Swampy' Marsh
Gender: Male
Known for: Acting
Birthday: December 9, 1960
Place of Birth: Santa Monica, California, USA

Biography

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.

Notable work

Filmography

Starring

Major Monogram (voice)
Major Francis Monogram (voice)
2025·
Spiked
(voice)
Major Monogram (voice)
Additional Voices (voice)
Major Monogram (voice)
Major Monogram / Additional Voices (voice)
Major Francis Monogram / Additional Voices (voice)
Major Hologram / Imperial Officer Jeff / Additional Voices
Major Francis Monogram (voice)
Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
Major Francis Monogram / Monogram-2 (voice)
Major Francis Monogram (voice) / Additional Voices
Major Monogram (voice)
Francis Monogram (voice)
(voice)

Production

2026·
Hey A.J.!
Executive Producer
Executive Producer
Creator, Writer
Executive Producer, Writer
Writer, Executive Producer, Characters
Creator, Story, Executive Producer
Executive Producer
Characters, Creator
Writer, Executive Producer, Sequence Supervisor
Additional Writing, Story
Creator, Story, Writer, Executive Producer, Director
Associate Producer
Additional Writing, Director, Storyboard Artist