The twenty-first season of Thomas & Friends aired in the UK on 18th September 2017 and on 15th December 2017 in the US.


Screenshot UK title (top)
US title (bottom)
Written by Original UK release date Episode number #
SpringtimeforDieselSpringtime for DieselDavey Moore18th September 2017#01
Daisy's springs need fixing after Diesel bumps her, and when the rumors spread about Daisy not being able to be mended, starts to worry Diesel.
AMostSingularEngineA Most Singular EngineDavey Moore19th September 2017#02
Diesel causes trouble between Daisy and Harvey by spreading rumors.
DowagerHatt'sBusyDayDowager Hatt's Busy DayLee Pressman20th September 2017#03
Dowager Hatt runs the railway while Sir Topham is away, but causes confusion and delay.
StuckinGearStuck in GearDavey Moore21st September 2017#04
A branch gets stuck in the gears of Harvey's crane.
RunawayEngineRunaway EngineHelen Farrall22nd September 2017#05
After mocking the way she was speaking up for herself, Stephen thinks that Millie ran away after hurting her feelings.
PAProblemsP.A. ProblemsLee Pressman25th September 2017#06
The Fat Controller/Sir Topham Hatt's new public address system causes havoc at Knapford station.
HastyHannahHasty HannahLee Pressman26th September 2017#07
A new coach temporarily replaces Henrietta while she is at the works.
CrankyattheEndoftheLineCranky at the End of the LineLee Pressman27th September 2017#08
Cranky thinks he will be replaced by a big, new, fancy crane.
NewCraneontheDockNew Crane on the DockLee Pressman28th September 2017#09
Cranky competes against Carly the new crane when she starts taking all his work.
UnscheduledStopsUnscheduled StopsHelen Farrall29th September 2017#10
Thomas starts making unscheduled stops for his passengers, which in turn delays others.
Philip'sNumberPhilip's NumberLee Pressman2nd October 2017#11
Philip tries to discover why he has the number 68 painted on his side after being teased about it.
TheFastestRedEngineonSodorThe Fastest Red Engine on SodorHelen Farrall3rd October 2017#12
After Rosie is repainted red, she and James have a race.
AShedforEdwardA Shed for EdwardLee Pressman4th October 2017#13
Edward searches for a new shed while his berth at Tidmouth is being repaired.
TheBigFreezeThe Big FreezeHelen Farrall1st December 2017#14
When a big freeze hits Sodor, Diesel finally proves himself to be a hero.
EmilyintheMiddleEmily in the MiddleDavey Moore6th December 2017#15
Emily gets stuck in the middle while helping Donald and Douglas.
TerenceBreakstheIceTerence Breaks the IceLee Pressman11th December 2017#16
Terence takes a shortcut across a frozen lake while collecting Christmas trees.
Daisy'sPerfectChristmasDaisy's Perfect ChristmasDavey Moore18th December 2017#17
Daisy is disappointed when her Christmas does not go exactly as planned.
ConfusedCoachespromoConfused CoachesHelen Farrall22nd December 2017#18
Spencer and Gordon upset their passengers when their competitive behaviour gets out of hand.



Characters Introduced





  • Arc Productions had produced the first seven episodes and Terence Breaks the Ice before their bankruptcy.
  • This season contains the 500th episode of the show, P.A. Problems.
  • This is the third season not to have Thomas' name titled in any of the episodes, the first being the fifteenth season and the second being the twentieth season.
  • This season marks the first of many things:
    • Ian McCue's first season as creative executive and the first season to have him as part of the voice cast.
    • Micaela Winter's first season as producer for the series.
    • Sukhmani Kaur's first season as assistant production manager.
    • Zahara Andrews' first season as production co-ordinator.
    • Alan Kennedy's first season as director of post-production.
    • Ryan Quaglia's first season as post-production editor.
    • Gavin Ebedes' first season as supervising editor.
    • Terence, Bulgy and Farmer Finney's first appearances in full CGI.
    • Hackenbeck Tunnel's first appearance in full CGI.
    • The first time in the television series in which Big Mickey appears with a face.
    • The first season to have no episodes written by Andrew Brenner despite being the head writer.
    • The first season since Season 15 not to introduce any new engines.
    • The first season to have episodes fully animated by Jam Filled.
    • The first time Stepney being mentioned since the twelth season, but was only mentioned in a music video.
  • This season also marks the last of several things:
    • Mark Moraghan's last season as narrator for the UK and US dubs.
    • The last season to utilise the original Thomas storytelling format.
    • Boris Andreev's last season as art director.
    • Alan Kennedy's last season as post-production supervisor.
    • Gavin Ebedes' last season as editor.
    • The last season to have episodes written by Helen Farrall.
    • The final season in which the Steam Team consists of all eight of its original members.
    • The final season to have Edward and Henry as members of the Steam Team.
    • The final season to have an episode where Thomas does not appear at all. From the twenty-second season onwards, he appears and speaks in all the episodes.
    • The last season to use the Engine Roll Call on a regular basis.
  • This is the shortest season of the main series to date, with there only being 18 episodes. There were 26 episodes planned, but eight were cut to make way for the development of Big World! Big Adventures! and the twenty-second season.
    • Currently, this is the only season to have fewer than 20 episodes.