- "The Character, for it's power, is the most powerful thing alive."
- ―Thomas Simpson
The following is a list of characters in The Thomas Simpson Show.
Main Goodland
- Annabelle
- Dawn Aztec
- Dawn Muller
- Betty Barrett
- Blasé
- Brendan
- Star Butterfly
- Gina Muller
- Jasper
- Jenna
- Kate
- Maddison
- Matt
- May
- Melissa
- Zoey Muller
- Nutsy
- Penelope
- Miss Piggy
- Taylor
- The Great King
- The Great Queen
- Thomas Simpson
- Tico
- Serena
- Sierra Tomic
- Vinny
- Westly
Sodor
- Bert
- Bill And Ben
- Donald and Douglas
- Duck The Great Western Engine
- Duncan
- Edward The Blue Engine
- Emily
- Gordon The Big Engine
- Henry The Green Engine
- James The Red Engine
- Mike
- Oliver The Great Western Engine
- Percy The Small Engine
- Philip
- Rex
- Rheneas
- Ryan
- Skarloey
- Sir Handel
- Thomas The Tank Engine
- Toby The Tram Engine
- Peter Sam
- Stanley
Springfield
- Mr Burns
- Carl Carlson
- Barney Gumble
- Lenny Leonard
- Moe
- Number One
- Bart Simpson
- Homer Simpson
- Lisa Simpson
- Marge Simpson
- Maggie Simpson
Quahog
- Brian Griffin
- Lois Griffin
- Peter Griffin
- Stewie Griffin
Bigg City Port
- Sunshine
- Ten Cents
- Top Hat
Care-A-Lot
- Bedtime Bear
- Best Friend Bear
- Cheer Bear
- Friend Bear
- Funshine Bear
- Grumpy Bear
- Harmony Bear
- Heartsong Bear
- Hopeful Heart Bear
- Laugh-A-Lot Bear
- Love-A-Lot Bear
- Oopsy Bear
- Share Bear
- Shine Bright Bear
- Superstar Bear
- Surprise Bear
- Sweet Dreams Bear
- Tenderheart Bear
- Trueheart Bear
- Wish Bear
Evilland
- The Circus Brothers
- Ed
- Grizzle
- Ian
- John The Royal Engine
- The Prince
Melbourne
- Jason Aztec
- Phil Aztec
- Susan Aztec
- Beast Boy
- Cyborg
- Jess
- Morgan
- Raven
- Robin
- Starfire
- Troy
- Veronica
Townsville
- Alex
- Amy
- Blossom
- Bubbles
- Buttercup
- Chloe
Langley Falls
- Roger
- Francine Smith
- Stan Smith
Greenpatch
Mewni
- Edwina Butterfly
- King Butterfly
- Queen Butterfly
The 3rd Dimension
- The Prince's friend
The Puppet Saga
- Chelsea Carter
- Emily (The Puppet Saga)
- Kermit
- Daniel Mackay
- Thomas Muller (The Puppet Saga)
- Noah Tolmach
Trivia
- No trivia.