The sixth season of the television series aired in 2002. Michael Angelis and Alec Baldwin narrated the twenty-six episodes for the UK and US respectively. Michael Angelis also narrated two episodes for the US release of New Friends for Thomas and Other Adventures. Michael Brandon later redubbed eight episodes for the US.
- Salty's Secret - Salty is dismayed when he is sent to work at the quarry.
- Harvey to the Rescue - The engines tease Harvey for his unusual appearance, but he soon proves his worth.
- No Sleep for Cranky - Cranky is in a worse mood than ever when he is stuck with Salty, Bill and Ben for the night.
- A Bad Day for Harold the Helicopter/A Bad Day for Harold - Percy is stuck at a broken signal and Harold takes the mail all at once - with disastrous results.
- Elizabeth the Vintage Lorry - When Thomas breaks down near an old shed, he discovers a disused lorry named Elizabeth.
- The Fogman - Ordinarily, Cyril, the fogman, warns the engines that there is fog ahead in Misty Valley, but The Fat Controller replaces him with a fog horn.
- Jack Jumps In - Jack the front loader is eager to be really useful, but soon learns his mistake.
- A Friend in Need - Jack tries to prove his worth after Ned nearly causes an accident with the bridge.
- It's Only Snow - Thomas encounters trouble in the snow with his faulty snowplough.
- Twin Trouble - Donald and Douglas fall out after an accident.
- The World's Strongest Engine - Diesel returns and tries to prove that diesels are stronger than steam engines.
- Scaredy Engines - Thomas teases Percy, but when they're sent to the Smelters to collect a special load Thomas gets his just desserts.
- Percy and the Haunted Mine - Percy is spooked by a mine that sinks into the ground.
- Middle Engine - 'Arry and Bert play tricks on Percy and James by shunting trucks in front of them.
- James and the Red Balloon - Thomas and James are scared a hot-air balloon will steal their passengers.
- Jack Frost - James is frightened when he sees a snowed-under Percy and mistakes him for Jack Frost.
- Gordon Takes a Tumble - Salty gives Gordon advice, but Gordon refuses to listen.
- Percy's Chocolate Crunch - Percy complains when he is restricted to one washdown a day, but gets dirtier than ever when he takes a load to the chocolate factory.
- Buffer Bother - Bill is jealous when Ben gets brand-new buffers.
- Toby Had a Little Lamb - Duck is unable to get to Farmer McColl's Field during winter, so Toby must rescue the lambs.
- Thomas, Percy and the Squeak - Thomas is proud when he gets to transport the famous singer Alicia Botti instead of Percy, but soon learns his lesson.
- Thomas the Jet Engine/Thomas and the Jet Engine - Gordon boasts about being the fastest engine on Sodor, but Thomas soon proves him wrong.
- Edward the Very Useful Engine/Edward the Really Useful Engine - Edward is old, but that doesn't stop him from helping Gordon and Duck.
- Dunkin' Duncan - Duncan gets too impatient at the incline and end up falling into a muddy ditch.
- Rusty Saves the Day - Rusty helps mend Rheneas and Skarloey's line, with Elizabeth's help.
- Faulty Whistles - Duncan loses his whistle and the replacement is very musical.
- Donald and Douglas
- Bill and Ben
- 'Arry and Bert
- Peter Sam
- Sir Topham Hatt
- Stephen Hatt
- Stepney (does not speak)
- Annie and Clarabel (do not speak)
- Henrietta (does not speak)
- Terence (does not speak)
- Jem Cole (does not speak)
- Oliver (cameo)
- George (cameo)
- Tiger Moth (cameo)
- Dowager Hatt (cameo)
- Bridget Hatt (cameo)
- Farmer Trotter (cameo)
- Mrs. Kyndley (cameo)
- The Refreshment Lady (cameo)
- Nancy (cameo)
- BoCo (music video cameo)
- Sir Handel (music video cameo)
- Duke (music video cameo)
- Bulstrode (music video cameo)
- Toad (deleted scene cameo)
- Oliver the excavator
- Miss Jenny
- The Foreman
- Cyril the Fogman
- Headmaster Hastings
- Farmer McColl
- Alicia Botti
- This season had its own special intro.
- This season was the last to feature the old Thomas the Tank Engine and Friends logo in the intro.
- This season has more narrators than any other.
- From this season onwards, all stories were written by individuals on a writing staff.
- This was the last season to feature an episode written by David Mitton.
- This was the first season to feature Steve Asquith as director.
- In 2006, Michael Angelis renarrated some episodes from this season with new music by Robert Hartshorne.
- Some of Michael Brandon's narrations used the new music whilst some had the classic music.
- This was Alec Baldwin's last season as narrator.