Jeff 'Swampy' Marsh
Born
December 9, 1960 (64 years old)
Known For
Acting
Place of Birth
Santa Monica, California, USA
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.
Known For
Spiked
(voice)
2025
How NOT to Draw
Major Monogram (voice) · (1 episode)
2022
Phineas and Ferb the Movie: Candace Against the Universe
Major Monogram (voice)
2020
Milo Murphy's Law
Additional Voices (voice) · (73 episodes)
2016
TV's Funniest Animated Stars: A Paley Center for Media Special
Self
2015
O.W.C.A. Files
Major Monogram / Additional Voices (voice)
2015
Phineas and Ferb: Last Day of Summer
Major Monogram (voice)
2015
Phineas and Ferb: Night of the Living Pharmacists
Major Francis Monogram (voice)
2014
Phineas and Ferb: Star Wars
Major Hologram / Imperial Officer Jeff / Additional Voices
2014
Phineas and Ferb Save Summer
Major Francis Monogram / Additional Voices (voice)
2014
I Know That Voice
Self
2014
Phineas and Ferb: Mission Marvel
Francis Major Monogram / Gordon Gutsofanemu / Additional Voices
2013
Phineas and Ferb: The Perry Files - Animal Agents
Major Monogram (voice)
2013
Phineas and Ferb: The Daze of Summer
2012
Phineas and Ferb The Movie: Across the 2nd Dimension
Major Francis Monogram / Monogram-2 (voice)
2011
Phineas and Ferb: Summer Belongs to You!
Major Francis Monogram (voice) / Additional Voices
2010
Phineas and Ferb Christmas Vacation!
Major Monogram (voice)
2009
Phineas and Ferb
Francis Monogram (voice) · (248 episodes)
2007
Bounty Hamster
(voice) · (1 episode)
2003
Aaagh! It's the Mr. Hell Show!
Josh (voice) · (13 episodes)
2001