The eighth season of the television series was the first to be produced by HiT Entertainment. The twenty-six episode season was first broadcast in 2004 and narrated by Michael Angelis in the UK and Michael Brandon in the US.
- Thomas and the Tuba - Thomas looks for the brass band's tuba player.
- Percy's New Whistle - Percy plays pranks with his whistle.
- Thomas to the Rescue - Diesel gives Thomas a hard time.
- Henry and the Wishing Tree - Henry learns to be careful what you wish for.
- James Gets a New Coat - James learns that pride comes before a fall.
- Thomas Saves the Day - Thomas tries to tackle a dangerous bend without Annie and Clarabel's assistance.
- Percy's Big Mistake - Percy is frightened he will be sent to the Scrapyards.
- Thomas, Emily and the Snowplough - Thomas ignores Emily's advice.
- Don't Tell Thomas - The engines are organising a party for Thomas but are not sharing the secret with him.
- Emily's New Route - Emily thinks there is a monster in Castle Loch, and tries to find another way round.
- Thomas and the Firework Display - Thomas helps James deliver the fireworks before the display is called off.
- Gordon Takes Charge - Gordon shows off to Percy.
- Spic and Span - Thomas and Percy try to beat the big engines in a cleanliness competition.
- Edward the Great - Edward races Spencer to The Duke and Duchess of Boxford's Summer House.
- Squeak, Rattle and Roll - Gordon tries to go slow so his squeaking and rattling won't be heard.
- Thomas and the Circus - Thomas tries to pull the circus train all by himself.
- Thomas Gets It Right - Thomas gets competitive about his deliveries.
- As Good as Gordon - Emily gets to pull the Express and tries to do the job as good as Gordon.
- Fish - Thomas gets into bother on Arthur's coastal branch with a long line of trucks.
- Emily's Adventure - Emily learns to use her manners after a storm has hit Sodor.
- Halloween - Emily accidentally scares herself as well as Thomas, 'Arry, and Bert.
- You Can Do it, Toby! - Toby gets nervous when he has to look after Wellsworth.
- Chickens to School - Lack of sleep gets the better of Thomas.
- Too Hot for Thomas - Thomas has to deliver ice cream ingredients.
- James Goes Too Far - James refuses to help his friends when he is given a very important job.
- Percy and the Magic Carpet - Percy is disappointed about delivering a carpet until Salty suggests that it could be magic.
- 'Arry and Bert
- Annie and Clarabel
- Sir Topham Hatt
- Farmer McColl
- Sodor Brass Band
- Murdoch (does not speak)
- Trevor (does not speak)
- Kuffy (does not speak)
- Lady Hatt (does not speak)
- Alicia Botti (does not speak)
- The Duke and Duchess of Boxford (do not speak)
- Henrietta (cameo)
- George (cameo)
- Caroline (cameo)
- Butch (cameo)
- Tiger Moth (cameo)
- Stephen Hatt (cameo)
- Bridget Hatt (cameo)
- Jem Cole (cameo)
- Farmer Trotter (cameo)
- Cyril the Fogman (cameo)
- The Refreshment Lady (cameo)
- Mrs. Kyndley (cameo)
- Nancy (cameo)
- Duck (music video cameo)
- Oliver (music video cameo)
- Toad (music video cameo)
- Rheneas (music video cameo)
- Rusty (music video cameo)
- Jeremiah Jobling (music video cameo)
- Donald and Douglas (deleted scene, mentioned)
- Bill and Ben (deleted scene)
- This is the first and only season to date that did not introduce any new non-human characters.
- This was the first season not to feature the Skarloey Railway since its debut, although Rusty and Rheneas made stock footage cameos in a song.
- This season was the first to use the new opening titles and theme.
- CiTV had a special opening theme when they broadcasted this season. This theme was also used on some US DVD releases.