The fifth season of the television series aired in 1998 and had twenty-six episodes narrated by Michael Angelis in the UK and Alec Baldwin in the US.
- Cranky Bugs - Cranky causes trouble for Thomas and Percy.
- Horrid Lorry - Three horrid lorries start taking over the engines' work.
- A Better View for Gordon - Gordon complains about the plainness of Kirk Ronan station.
- Lady Hatt's Birthday Party - The Fat Controller urgently needs to get to Lady Hatt's birthday party.
- James and the Trouble with Trees - James is careless around some trees
- Gordon and the Gremlin - "Gremlins" start causing problems for Gordon when Dowager Hatt visits.
- Bye George! - George causes grief for Rheneas, Skarloey, Percy, Thomas, Duck, and Gordon.
- Baa! - Percy meets a ram, who manages to help out when a station is trashed.
- Put Upon Percy - Percy complains that he is overworked and gets into a predicament in the mines.
- Toby and the Flood - Toby gets in a dangerous position when a dam bursts.
- Haunted Henry - Henry gets spooked on an old line.
- Double Teething Troubles - Derek, a malfunctioning diesel, causes more trouble than he is worth for Bill and Ben.
- Stepney Gets Lost - Stepney gets lost on the way home.
- Toby's Discovery - Toby goes exploring and makes several odd discoveries.
- Something in the Air - Henry ignores Thomas' warning about a dangerous line.
- Thomas, Percy and Old Slowcoach - Thomas and Percy save an old coach from scrap.
- Thomas and the Rumours/Thomas and the Rumors - When Harold is chosen to take a special visitor around Sodor, the engines fear they will be replaced.
- Oliver's Find - Oliver makes an amazing find on an old branch line whilst taking the mail.
- Happy Ever After - Percy makes a "good luck package" for Mrs. Kyndley's daughter's wedding.
- Sir Topham Hatt's Holiday - The Fat Controller goes on holiday, with disastrous results.
- A Surprise For Percy/A Big Surprise For Percy - Percy moans about his work in the mines, but he is headed for a surprise.
- Make Someone Happy - James tries to think of others and takes Mrs. Kyndley on a "mystery tour".
- Busy Going Backwards - Toad wants to go forwards for a change.
- Duncan Gets Spooked - Rusty tells Duncan a ghost story.
- Rusty and the Boulder - Thumper causes chaos when he dislodges a boulder.
- Snow - Rusty tells Thomas about snow and how Skarloey managed to survive it.
- This was the first season of several things:
- The first season not to have any episodes based on Railway Series stories by Wilbert and Christopher Awdry.
- Alec Baldwin's first season as narrator.
- The first season not to air on Shining Time Station due to the show's cancellation.
- The first season to use a Proteus 2000 to compose the music.
- The first season not to be dubbed in Finnish or Ukrainian.
- This was also the final season of several things:
- Britt Allcroft's final season as writer and producer.
- Angus Wright's last season as executive producer.
- The last season to be shown on Cartoon Network UK, besides syndicated episodes that would still be shown on the channel until 2001.
- The last season to be filmed completely in 4:3 full screen.
- This was also the only season of several things:
- The only season not to have Knapford Station as a destination.
- The only season to have Kirk Ronan as a destination.
- The only season where Donald appears without Douglas.
- The only season that Diesel does not appear in since his debut.
- David Maidment's only season as railway consultant and writer.
- Michael Angelis was not credited in the opening titles for the UK narration. However, he is credited as narrator in the Hindi narration, even though it was redubbed.
- Starting with this season up to Season 12, the brake sound effect from the 1964 film, The Train would be used when an engine put on the brakes.