Series 18

The eighteenth season of the television series began airing on August 25th, 2014 in the UK and on November 4th, 2014 in the US. It contained twenty-six episodes. Like the seventeenth season, five episodes were released on DVD in the US before airing on television. It concluded in the UK on July 31st, 2015.

Episodes

 * 1) Old Reliable Edward - The bigger engines tease Edward for being old and unreliable, especially Gordon.
 * 2) Not So Slow Coaches - Annie and Clarabel unexpectedly become part of Caitlin's high-speed train.
 * 3) Flatbeds of Fear - Salty tells the story of the "Flatbeds of Fear" which spooks the engines.
 * 4) Disappearing Diesels - Devious Diesel and the others hide from Paxton.
 * 5) Signals Crossed - Toby is nervous when the signal at Knapford stays red.
 * 6) Toad's Adventure - Toad has an adventure on the main line with James.
 * 7) Duck in the Water - James has to rescue Duck from a flood, but ends up making things a whole lot worse.
 * 8) Duck and the Slip Coaches - James runs into trouble with some slip coaches which are used on the Great Western Railway.
 * 9) Thomas the Quarry Engine - Thomas works at the quarry while Diesel takes Mavis to see the sights of Sodor.
 * 10) Thomas and the Emergency Cable - Thomas has to stop quickly when a passenger pulls the emergency cable.
 * 11) Duncan and the Grumpy Passenger - Duncan tries his best to stop a passenger from complaining.
 * 12) Marion and the Pipe - Marion thinks she's found an old Viking ship, but it turns out to be a water pipe which springs a leak.
 * 13) Missing Gator - Percy struggles to remember what Gator taught him about being brave.
 * 14) No Steam Without Coal - Bill and Ben run out of coal and need Timothy's help.
 * 15) Spencer's VIP - All the engines compete for a chance to take a VIP.
 * 16) Toad's Bright Idea - Toad has an idea to help Gator run safely at night.
 * 17) Long Lost Friend - Gator returns to the island where he has a touching reunion with Percy.
 * 18) Last Train for Christmas - Connor has the tricky task of getting all of his passengers from the mainland home in time for Christmas.
 * 19) Duncan the Humbug - Mr. Percival promises Duncan he can be first for a new coat of paint if he can stop grumbling for a day.
 * 20) The Perfect Gift - Percy tries to get Reg in the Christmas spirit.
 * 21) Emily Saves the World - Emily gets very excited when she's asked to deliver a globe to the Animal Park.
 * 22) Timothy and the Rainbow Truck/Timothy and the Rainbow Car - Bill and Ben send Timothy on a wild goose chase, but get more than they'd bargained for.
 * 23) Marion and the Dinosaurs - Marion is spooked by some lifelike models for the Earl's new Dinosaur Park.
 * 24) Samson at Your Service - Proud Samson learns to admit when he's in the wrong.
 * 25) Samson Sent for Scrap - Samson takes his job description a little too literally, causing confusion.
 * 26) Millie and the Volcano - Millie is cross when Samson and Harvey call her scared, so she teaches them a lesson.

Songs

 * It's Christmas Time
 * The Best Friends Express

Characters

 * Thomas
 * Edward
 * Henry
 * Gordon
 * James
 * Percy
 * Toby
 * Duck
 * Oliver
 * Bill and Ben
 * Harvey
 * Emily
 * Spencer
 * Stanley
 * Hiro
 * Charlie
 * Scruff
 * Stephen
 * Connor
 * Caitlin
 * Porter
 * Gator
 * Timothy
 * Diesel
 * Mavis
 * Salty
 * Den
 * Dart
 * Paxton
 * Sidney
 * Stafford
 * Skarloey
 * Rheneas
 * Peter Sam
 * Duncan
 * Victor
 * Luke
 * Millie
 * Rusty
 * Marion
 * Annie and Clarabel
 * Henrietta
 * Toad
 * Rocky
 * Bertie
 * Cranky
 * Captain
 * Owen
 * Reg
 * Sir Topham Hatt
 * Mr. Percival
 * Dowager Hatt
 * Sir Robert Norramby
 * The Wellsworth Stationmaster
 * Gator's Driver
 * Thomas' Guard
 * The Teacher
 * The Blond-haired Boy
 * The Schoolchildren
 * The Groundsman
 * The Dock Manager
 * The Lady with the Big Hat
 * Some Workmen
 * Whiff (does not speak)
 * Belle (does not speak)
 * Kevin (does not speak)
 * Harold (does not speak)
 * The Duchess of Boxford (does not speak)
 * Rosie (cameo)
 * Ferdinand (cameo)
 * 'Arry and Bert (cameo)
 * Norman (cameo)
 * Sir Handel (cameo)
 * Winston (cameo)
 * Merrick (cameo)
 * Farmer McColl (cameo)
 * The Bird Watcher (cameo)
 * Flynn (mentioned)
 * Queen Elizabeth II (mentioned)
 * Sodor United Football Team (mentioned)
 * Alicia Botti (not named; mentioned)
 * Bash (learning segment)

Characters Introduced

 * Samson
 * Slip Coaches
 * The Welsh Bird Watcher
 * The Grumpy Passenger
 * The Deputy Minister
 * The Postman

UK and AUS

 * Mark Moraghan as the narrator
 * Ben Small as Thomas, Toby, Rheneas, the Troublesome Trucks and Owen
 * Keith Wickham as Edward, Henry, Gordon, James, Percy, Harvey, Salty, Den, Stafford, Skarloey, Bertie, Captain, Sir Topham Hatt, Mr. Percival, Dowager Hatt, the Wellsworth Stationmaster, Some Workmen, one of Sir Topham Hatt's Assistants, Some Passengers, Thomas' Guard, the Grumpy Passenger, Gator's Driver, the Steamworks Worker, the Groundsman, the Postman and the Bird Watcher
 * Teresa Gallagher as Emily, Mavis, Annie, Clarabel, the Teacher, the Blond-haired Boy, the Lady with the Big Hat, Station Speakers, Some Passengers and Some Children
 * Kerry Shale as Diesel
 * Steven Kynman as Duck, Porter, Paxton, Dart, Peter Sam and the third Slip Coach
 * Togo Igawa as Hiro
 * Michael Legge as Luke
 * Jonathan Forbes as Connor
 * Rebecca O'Mara as Caitlin and the second Slip Coach
 * Matt Wilkinson as Stanley, Spencer, Charlie, Scruff, Rusty, Rocky, Cranky, the Dock Manager, Some Workman and the Man with the Hat
 * Miranda Raison as Millie and the Knapford station speaker
 * Jonathan Broadbent as Bill and Ben
 * Clive Mantle as Gator
 * Maggie Ollerenshaw as Henrietta
 * Olivia Colman as Marion
 * Bob Golding as Stephen and Sidney
 * Tim Whitnall as Timothy, Reg, and the Deputy Minister
 * Joe Mills as Oliver, Toad, and the Welsh Bird Watcher
 * Tom Stourton as Duncan
 * David Bedella as Victor
 * Robert Wilfort as Samson
 * Mike Grady as Sir Robert Norramby

USA

 * Mark Moraghan as the narrator
 * Martin Sherman as Thomas, Percy, and Diesel
 * William Hope as Edward, Toby, Rocky and the Dock Manager
 * Kerry Shale as Henry, Gordon, James, Scruff, Sir Topham Hatt, Mr. Percival and Some Workmen
 * Keith Wickham as Harvey, Salty, Den, Stafford, Skarloey, Bertie, Captain, Dowager Hatt, the Wellsworth Stationmaster, Some Passengers, Thomas' Guard, the Grumpy Passenger, the Groundsman, the Postman and the Bird Watcher
 * Teresa Gallagher as Mavis, Annie, Clarabel, the Teacher, the Lady with the Big Hat, Station Speakers, Some Passengers and Some Children
 * Jules de Jongh as Emily, The Blond-haired Boy, Some Passengers and Some Children
 * Steven Kynman as Duck, Paxton, Dart, Peter Sam and the third Slip Coach
 * Jonathan Forbes as Connor
 * Rebecca O'Mara as Caitlin and the second Slip Coach
 * Togo Igawa as Hiro
 * Ben Small as Charlie, Rheneas, the Troublesome Trucks and Owen
 * Michael Legge as Luke
 * Miranda Raison as Millie and the Knapford Station Speaker
 * Jonathan Broadbent as Bill and Ben
 * Bob Golding as Stephen and Sidney
 * David Menkin as Stanley and Porter
 * Glenn Wrage as Spencer, Cranky, one of Sir Topham Hatt's Assistants, Gator's Driver and the Steamworks Worker
 * Matt Wilkinson as Rusty and some Workmen
 * Olivia Colman as Marion
 * Maggie Ollerenshaw as Henrietta
 * Clive Mantle as Gator
 * Tim Whitnall as Timothy, Reg, the Deputy Minister and the Man with the Hat
 * Joe Mills as Oliver, Toad, and the Welsh Bird Watcher
 * Tom Stourton as Duncan
 * David Bedella as Victor
 * Robert Wilfort as Samson
 * Mike Grady as Sir Robert Norramby

Trivia

 * This season marked the last of a few things:
 * The last season to have Ben Small and Martin Sherman as part of the voice cast. John Hasler and Joseph May took over the role of Thomas for their respective dubs in The Adventure Begins, Christopher Ragland took over the role of Percy in the US and the Troublesome Trucks in both the UK and US, Rob Rackstraw took over the role of Toby in the UK, David Menkin took over the role of Stanley in the US, Kerry Shale took over the roles of Diesel in the US and Flynn in both the UK and US, and Hasler took over the role of Rheneas. To date, it is currently unknown who will voice Charlie in the US, Ferdinand in the UK, and Owen in both the US and the UK.
 * The last season to have Sir Topham Hatt and James voiced by Kerry Shale in the US. Keith Wickham and Rob Rackstraw took over the respective roles beginning in The Adventure Begins. Shale would continue to voice Henry, Gordon, Harold and others.
 * This season also marks the first of a few things:
 * The first season to feature David Menkin as Stanley.
 * Henrietta gains a face for the first time in the television series.
 * The first season to have Tim Whitnall, Olivia Colman, Clive Mantle, Maggie Ollerenshaw, Joe Mills, Tom Stourton, and Robert Wilfort as part of the voice cast.
 * The first season since its introduction where the Sodor Search and Rescue Centre did not appear, although it was mentioned in Millie and the Volcano.