Jeffrey “Jeff/Swampy” Marsh is a director, writer, producer, animator, and voice actor. Co-Creator of Phineas and Ferb and it's sequel show, Milo Murphy's Law, with Dan Povenmire, he has directed, written, and acted in this Disney Channel Original Series. In Phineas and Ferb, he portrays the voice of Francis Monogram, the commander of Perry the Platypus. In Milo Murphy's Law he voices the time traveler, Balthazar Cavendish. From the both show’s inception, Swampy has been one of the main songwriters of both series, along with Dan Povenmire and Martin Olson. Before working for Disney, he was one of the writers of the Nickelodeon program Rocko’s Modern Life


  • Nominated along with Dan Povenmire for two Emmy awards: “Outstanding Original Main Title Theme Music” and “Outstanding Original Music and Lyrics” (for “Ain’t Got Rhythm”)
  • Nominated along with executive producer Dan Povenmire, director Zac Moncrief, et al., for the Emmy Award for “Outstanding Short-Formed Animation Program” for Phineas and Ferb (episode: “The Monster of Phineas-n-Ferbenstein”)

Disney Roles



  • He got the nickname "Swampy" while attending college in England, in reference to his surname. He added the nickname as an intertitle in his credited and preferred name, Jeff "Swampy" Marsh, as a means of making it longer than most others' names, at fifteen letters.
  • In the Phineas and Ferb series, his nickname has been used in some episodes (such as on a truck in "The Magnificent Few", it said Swampy's Farm Fresh Milk. Also, the drummer of Love Handel uses "Swampy" as his stage name).
  • There are several references to Swampy throughout both of his shows:

Phineas and Ferb Wiki-wordmark This page uses Creative Commons Licensed content from the The Phineas and Ferb Wiki. The list of authors can be seen in the page revision history (view authors). As with Disney Wiki, the text of The Phineas and Ferb Wiki is available under the CC-by-SA Free Documentation License.
Community content is available under CC-BY-SA unless otherwise noted.

Fandom may earn an affiliate commission on sales made from links on this page.

Stream the best stories.

Fandom may earn an affiliate commission on sales made from links on this page.

Get Disney+