The third season of the television series first premiered on VHS in 1991 in the UK before airing on TV. It first aired in the US in 1991 on Shining Time Station, with the last 10 episodes following in 1993. The whole season first aired in the UK from February to July 1992. All twenty-six episodes were narrated by Michael Angelis in the UK and by George Carlin in the US and New Zealand.
- A Scarf for Percy - Percy wants to wear a scarf, but changes his mind after an accident with a baggage trolley.
- Percy's Promise - Percy makes a promise, to Thomas, that despite a terrible storm, he will get Annie, Clarabel, and the Sunday school home safely.
- Time for Trouble - James takes over Gordon's work, but is humbled after having to push a stranded Toby to the Works.
- Gordon and the Famous Visitor - Gordon is jealous of a vistor's high-speed record, and loses his dome trying to go as fast.
- Donald's Duck - Duck gets cross at Donald's teasing and plays a trick on him, which soon backfires.
- Thomas Gets Bumped - Thomas is worried Bertie will take his passengers, after he is sent to the yard to wait until the track is mended.
- Thomas, Percy and the Dragon - Thomas gets even with Percy's ghostly prank with the help of a paper Chinese dragon.
- Diesel Does it Again - Diesel returns to cause trouble for Percy and Duck at the harbour.
- Henry's Forest - Henry is upset when the forest is decimated in a storm, but the Fat Controller and Toby puts things right.
- The Trouble with Mud - Gordon is given goods work after refusing to get a wash down and spraying James with mud, but ends up helping James up the hill.
- No Joke for James - James tricks Thomas into giving him Gordon's express, but soon regrets his trick.
- Thomas, Percy and the Post Train/Thomas, Percy and the Mail Train - Thomas and Percy try to save their post trains from being replaced by Harold.
- Trust Thomas - Thomas promises to help mend Bertie's roads, but must help himself first after Gordon and James get him into bother.
- Mavis - Mavis, a new diesel, proves to be arrogant and troublesome, and refuses to listen to Toby's advice.
- Toby's Tightrope - Mavis redeems herself after Toby's trucks push him onto an unsafe bridge.
- Edward, Trevor and the Really Useful Party - Edward and Trevor help the vicar with a garden party, while Bertie runs into bother in the mud.
- Buzz, Buzz/James goes Buzz Buzz - James calls BoCo a "buzzbox", but becomes one himself after a beehive is broken by a porter.
- All at Sea - Duck wishes to travel to the horizon, but after helping an injured workman he changes his mind.
- One Good Turn - Bill and Ben fall out over an incident with a turntable.
- Tender Engines - Henry boasts he deserves an extra tender for his hard work, but Duck brings him down to earth again.
- Escape - Douglas rescues a Great Western engine named Oliver and a brakevan named Toad from the scrapyard.
- Oliver Owns Up - Oliver becomes conceited from all the praise and attention from the other engines, but the trucks teach him a lesson.
- Bulgy - A railway-hating double-decker bus attempts to steal Duck and Oliver's passengers.
- Heroes - Bill and Ben cause confusion at the harbour, but become heroes after saving workers during a rockslide at the quarry.
- Percy, James and the Fruitful Day - Percy and James have an adventure with a fruit train.
- Thomas and Percy's Christmas Adventure/Thomas and Percy's Mountain Adventure - Thomas and Percy work together to give a snowed-down village a Merry Christmas.
- Thomas' Anthem (with footage from season 3 only)
- Donald and Douglas
- Bill and Ben
- Annie and Clarabel
- Sir Topham Hatt
- The Vicar of Wellsworth
- Jeremiah Jobling (not named)
- Jem Cole (not named)
- Henrietta (does not speak)
- Lady Hatt (not named; does not speak)
- Stephen Hatt (cameo)
- Bridget Hatt (cameo)
- Mrs. Kyndley (cameo)
- Farmer Finney (cameo)
- The Firelighter (mentioned)
- Father Christmas (mentioned in the UK version)
- Daisy (mentioned in music video)
- The Chinese Dragon
- The New Signalman
- The Railway Foreman
- The Quarry-master
- Toad (does not speak)
- The Railway Society (do not speak)
- The Injured Sailor (does not speak)
- City of Truro (not named; does not speak)
- Flying Scotsman (tenders only; not named; does not speak)
- Farmer Trotter (cameo)
- Bulgy's friend (mentioned)
- This was the first season of several things:
- The first season narrated by Michael Angelis in the UK and George Carlin in the US, and the first narrated by the latter that had not been previously released with Ringo Starr's narrations.
- The first season to have episodes not based on material by either Awdry.
- Britt Allcroft's first season as producer.
- Angus Wright's first season as executive producer.
- The first season to feature TUGS models.
- This season was the first to use the EMU Proteus 2 Orchestral to create the music. However, some of the music made with the Roland Jupiter 6 synthesizer for the first and second season was used.
- The first season to start airing in one year and finish in another.
- The first season dubbed in Finnish.
- The first season to have slow motion effects.
- The biggest space of time between two seasons airing is between Season 2 and Season 3. Season 2 first aired back in 1986, and Season 3 in 1992.
- In the Ukrainian version, Michael Angelis and George Carlin's voices can be heard in the background, as a dubbing track wasn't used. The first thirteen episodes have George Carlin's voice while the last thirteen episodes have Michael Angelis' voice. Angelis is also credited as narrator in the first 13 Season 3 episodes despite Carlin's narration in the background and the episode being redubbed.
- For much of the season, Tidmouth Sheds appears to be much larger on the inside than usual. While all the exterior scenes depict the shed with the usual six berths, there are nine tracks seen in most interior views.
- This is the only season that has George Carlin's narration on VHS in New Zealand. However when the Season 3 episodes were aired in New Zealand, Michael Angelis' narration was used instead. This is also the case when The Complete Third Series was released on DVD in New Zealand.
- Model maker John Holmes did not receive credit for working on this season until 1992.
- At the very end of Michael Angelis' early narrations, the credits were shown with a still of the final shot of each episode. When shown on TV and in future video and DVD releases, the credits were shown alongside a still of Thomas.
- This was the last season to be shown on ITV until 2002 when Season 6 was shown.
- This season as produced in association with Fuji Television Network, Inc., as indicated by a message at the end of each episode. In 1991 airings, the message is in white, while in 1992 airings, it is yellow.
- According to The Thomas the Tank Engine Man, it cost £1.3 million to produce all 26 episodes.