Season 15

The fifteenth season of the television series aired during March 2011 in the UK and between April and June in the US. This season has a total of twenty episodes.

Specials

 * Day of the Diesels

Song

 * Hear the Engines Coming

Characters

 * Thomas
 * Edward
 * Henry
 * Gordon
 * James
 * Percy
 * Toby
 * Emily
 * Spencer
 * Rosie
 * Whiff
 * Stanley
 * Hiro
 * Charlie
 * Bash and Dash
 * Ferdinand
 * Diesel
 * Mavis
 * 'Arry and Bert
 * Salty
 * Victor
 * Belle
 * Flynn
 * Den
 * Dart
 * Rocky
 * Bertie
 * Butch
 * Kevin
 * Harold
 * Cranky
 * Captain
 * Sir Topham Hatt
 * Lady Hatt
 * Dowager Hatt
 * Farmer McColl
 * The Duke of Boxford
 * Mr. Bubbles
 * The Sodor Search and Rescue Centre Manager
 * The Maithwaite Stationmaster
 * Workmen
 * The Schoolchildren
 * The Ginger-haired Boy
 * The Blonde-haired Boy
 * Norman (not named)
 * The Duchess of Boxford (does not speak)
 * Scruff (cameo)
 * Paxton (cameo)
 * Annie and Clarabel (cameo)
 * Henrietta (cameo)
 * Trevor (cameo)
 * Stephen Hatt (cameo)
 * Bridget Hatt (cameo)
 * Mr. Percival (cameo)
 * Jem Cole (cameo)
 * Alicia Botti (cameo)
 * Sodor Brass Band (cameo)
 * The Dairy Manager (cameo)
 * The Photographer (cameo)
 * The Bargeman (cameo)
 * The Fireman (cameo)
 * The Knapford Stationmaster (cameo)
 * The Teacher (cameo)
 * The Bird Watcher (cameo)
 * The Railway Inspector (cameo)
 * The Tree Specialists (cameo)
 * Three Sodor United Players (cameo)
 * The Laundry Lady (cameo)
 * Farmer Trotter (mentioned)
 * Father Christmas (mentioned)
 * Sir Handel (original concept only)
 * Peter Sam (original concept only)
 * Duke (original concept only)

Characters Introduced

 * The Railway Coal Inspector
 * Dowager Hatt's Friends (do not speak)
 * Albert's Wife (cameo)

Half hour format
When season 15 aired on PBS in the US and Nick Jr. in the UK, each broadcast airs two episodes, a song & a Down at the Station segments.

Exciting Friends

 * Gordon and Ferdinand
 * Song: All You Need
 * Toby and Bash

Kindness with Friends

 * Percy's New Friends
 * Song: All You Need
 * Emily and Dash

Learning Together

 * James to the Rescue
 * Song: Go, Go Thomas
 * Down at the Station: The Steam Engine
 * Happy Hiro

Happy Engines

 * Henry's Happy Coal
 * Song: Go, Go Thomas
 * Down at the Station: Coal
 * Edward the Hero

Fun in the Snow

 * Let it Snow
 * Song: TBA
 * Percy the Snowman

Helping Each Other

 * Stop that Bus!
 * Song: Roll Along
 * Down at the Station: Passengers
 * Spencer the Grand

Laughing Together

 * Big Belle
 * Song: Go, Go Thomas!
 * Stuck on You

Slow Down!Edit

 * Wonky Whistle
 * Song: Hear the Engines Coming
 * Down at the Station: Going Backwards
 * Up, Up and Away!

Special Times

 * Surprise, Surprise
 * Song: TBA
 * Tree Trouble

Being Useful

 * Kevin the Steamie
 * Song: Hear the Engines Coming
 * Down at the Station: Fireman
 * Fiery Flynn

UK and AUS
as Edward, Henry, Gordon, James, Percy, Whiff, Dash, Salty, Den, Harold, Captain, Sir Topham Hatt, Dowager Hatt, Mr. Bubbles and the Railway Coal Inspector as Spencer, Stanley, Charlie, Bash, Victor, Cranky, Kevin, Farmer McColl, the Duke of Boxford, the Maithwaite Stationmaster and the Sodor Search and Rescue Centre Manager
 * Michael Angelis as the narrator
 * Ben Small as Thomas, Toby and Ferdinand
 * Teresa Gallagher as Emily, Rosie, Belle, Mavis, Lady Hatt and the Ginger-haired Boy
 * Keith Wickham
 * Matt Wilkinson
 * Rupert Degas as Den (Fiery Flynn only), Dart, Flynn, Bertie and Butch
 * Togo Igawa as Hiro
 * Kerry Shale as Diesel, 'Arry, Bert and Norman
 * William Hope as the Steamworks Worker and the Farm Hands

US and CAN
as Edward, Toby, Whiff, Bash, Rocky, the Duke of Boxford, the Maithwaite Stationmaster, the Steamworks Worker and the Farm Hands
 * Michael Brandon as the narrator, Diesel and Mr. Bubbles
 * Martin Sherman as Thomas and Percy
 * Jules de Jongh as Emily, Rosie, Mavis and Lady Hatt
 * William Hope
 * Kerry Shale as Henry, Gordon, James, Dash, 'Arry, Bert, Norman, Harold, Kevin, Sir Topham Hatt, and the Railway Coal Inspector
 * Keith Wickham as Salty, Den, Captain and Dowager Hatt
 * Ben Small as Stanley
 * Teresa Gallagher as Belle and the Ginger-haired Boy
 * Rupert Degas as Den (Fiery Flynn only), Dart, Flynn and Bertie
 * Togo Igawa as Hiro
 * David Bedella as Victor
 * Glenn Wrage as Spencer, Charlie, Ferdinand, Cranky, Butch and the Sodor Search and Rescue Centre Manager

Trivia

 * This season was supposed to be shown after Day of the Diesels, but was brought forwards for unknown reasons.
 * This season marks the first of a few things:
 * Butch's first speaking role in the television series.
 * Trevor's first appearance in full CGI.
 * Arlesdale End, Castle Loch, the Fishing Village and Wellsworth's first appearances in full CGI.
 * The first and only season to have Rupert Degas as Butch in the UK. Matt Wilkinson later took over this role in the sixteenth season.
 * The first season to have Rupert Degas as part of the voice cast.
 * The first season with Season 20 being the second not to have Thomas' name titled in any of the episodes.
 * The first and only season to date, where Thomas, Gordon and Percy have more roles than the rest of the Steam Team.
 * This season marks the last of a few things:
 * The last season in which Christopher Skala was executive producer.
 * The last season in which Jo Jordan was creative producer.
 * The last season to have Jukka Voutilaninen voice Hiro in the Finnish dub.
 * Percy's whistle now budges up and down when he uses it.
 * Jules de Jongh is mentioned in the UK credits despite not having a role.
 * On Netflix UK, this series was listed as being season 13. The mistake was later corrected.
 * In Finland, this season was shown on the website MTV Juniori before airing on television.