
Jeff 'Swampy' Marsh
Acting
Born 1960-12-09 · 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.
Filmography

Spiked
Jul 3, 2025

Phineas and Ferb the Movie: Candace Against the Universe
Aug 27, 2020

TV's Funniest Animated Stars: A Paley Center for Media Special
Dec 7, 2015

O.W.C.A. Files
Nov 9, 2015

Phineas and Ferb: Last Day of Summer
Jun 15, 2015

Phineas and Ferb: Night of the Living Pharmacists
Oct 4, 2014

Phineas and Ferb: Star Wars
Jul 26, 2014

Phineas and Ferb Save Summer
Jun 9, 2014

I Know That Voice
Jan 7, 2014

Phineas and Ferb: Mission Marvel
Aug 16, 2013

Phineas and Ferb: The Perry Files - Animal Agents
Feb 26, 2013

Phineas and Ferb: The Daze of Summer
Feb 7, 2012

Phineas and Ferb The Movie: Across the 2nd Dimension
Aug 5, 2011

Phineas and Ferb: Summer Belongs to You!
Aug 2, 2010

Phineas and Ferb Christmas Vacation!
Dec 7, 2009