Prior to creating shows for Disney, he worked on shows such as The Simpsons, Rocko's Modern Life, King of the Hill and Postman Pat.
Currently, Marsh is the creator and showrunner the Prime Video children's animated series Pete the Cat.
Tropes associated with Jeff "Swampy" Marsh's works:
- Descended Creator: In all three of his shows, Jeff has done voicework with Major Monogram, Cavendish, and Pete's Dad.
- Once an Episode: A common staple in his Disney shows.
- Strictly Formula: His and Dan Povenmire's cartoons tend to follow a certain pattern and formula in most episodes. While it is most noticeable in Phineas and Ferb, even Milo Murphy's Law is prone to this with Once an Episode gags.
- What Could Have Been: Phineas and Ferb was first conceived in 1993, but lack of faith in the project and additional commitments from the show's creators (hoping to get their big break that way), delayed the show for more than 10 years as he and Dan pitched it to networks like Fox Kids, Cartoon Network, and Nickelodeon, all of whom rejected the pilot. It was then pitched to Disney Channel in 2006, and it finally premiered in 2007.
- Write Who You Know:
- Ferb is based on two different people known by him and Dan - a friend of theirs with the same name who was very good with tools, and an uncle of Jeff who rarely said much but always made profound statements.
- The idea of Phineas and Ferb being step-brothers was partiallynote inspired by the fact that Marsh himself came from a reconstituted family. In fact, Jeff has gone on record saying that Lawrence is very similar to his own stepfather.
- The references to Britain are based on the time that Swampy spent living in England. The various references to the Dutch sprinkled throughout are based on the fact that Swampy's wife is from the Netherlands.
