Acting · Santa Monica, California, USA · Born December 9, 1960
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.
TVAgent P Under C
2026
as Major Monogram (voice)
MovieSpiked
2025
as Big Boss Croc / Exterminator (voice)
TVHow Not to Draw
2022
as Major Monogram (voice)
MoviePhineas and Ferb the Movie: Candace Against the Universe
2020
as Major Monogram (voice)
TVMilo Murphy's Law
2016
as Additional Voices (voice)
MovieTV's Funniest Animated Stars: A Paley Center for Media Special
2015
as Self
MovieO.W.C.A. Files
2015
as Major Monogram / Additional Voices (voice)
MoviePhineas and Ferb: Last Day of Summer
2015
as Major Monogram (voice)
MoviePhineas and Ferb: Night of the Living Pharmacists
2014
as Major Francis Monogram (voice)
MoviePhineas and Ferb: Star Wars
2014
as Major Hologram / Imperial Officer Jeff / Additional Voices
MoviePhineas and Ferb Save Summer
2014
as Major Francis Monogram / Additional Voices (voice)
MovieI Know That Voice
2014
as Self
MoviePhineas and Ferb: Mission Marvel
2013
as Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
MoviePhineas and Ferb: The Perry Files - Animal Agents
2013
as Major Monogram (voice)
MoviePhineas and Ferb: The Daze of Summer
2012
MoviePhineas and Ferb The Movie: Across the 2nd Dimension
2011
as Major Francis Monogram / Monogram-2 (voice)
MoviePhineas and Ferb: Summer Belongs to You!
2010
as Major Francis Monogram / Additional Voices (voice)
MoviePhineas and Ferb Christmas Vacation!
2009
as Major Monogram (voice)
TVPhineas and Ferb
2007
as Francis Monogram (voice)
TVBounty Hamster
2003
as (voice)
TVAaagh! It's the Mr. Hell Show!
2001
as Josh (voice)
MovieUntitled Phineas and Ferb Movie
as Major Francis Monogram (voice)
