
Jeff 'Swampy' Marsh
Acting
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

2007
Phineas and Ferb
2007 · tv

2016
Milo Murphy's Law
2016 · tv

2020
Phineas and Ferb the Movie: Candace Against the Universe
2020 · movie

2011
Phineas and Ferb The Movie: Across the 2nd Dimension
2011 · movie

2026
Agent P Under C
2026 · tv

2013
Phineas and Ferb: Mission Marvel
2013 · movie

2001
Aaagh! It's the Mr. Hell Show!
2001 · tv

2012
Phineas and Ferb: The Daze of Summer
2012 · movie

2022
How Not to Draw
2022 · tv

2014
Phineas and Ferb: Star Wars
2014 · movie

2003
Bounty Hamster
2003 · tv

2014
I Know That Voice
2014 · movie

2015
O.W.C.A. Files
2015 · movie

2010
Phineas and Ferb: Summer Belongs to You!
2010 · movie

2014
Phineas and Ferb: Night of the Living Pharmacists
2014 · movie

2015
TV's Funniest Animated Stars: A Paley Center for Media Special
2015 · movie

2013
Phineas and Ferb: The Perry Files - Animal Agents
2013 · movie

2009
Phineas and Ferb Christmas Vacation!
2009 · movie

2014
Phineas and Ferb Save Summer
2014 · movie

2015
Phineas and Ferb: Last Day of Summer
2015 · movie

2025
Spiked
2025 · movie

—
Untitled Phineas and Ferb Movie
— · movie