Emil is a Stirling Single tender engine. She works primarily on the Main Line and Thomas branch line, and has her own rake of coaches.
When Emily was new to Sodor, she was ignored by the other engines for pulling Annie and Clarabel without Thomas' permission or knowledge. The matter was resolved after she saved both Thomas and Oliver from a nasty accident on the cross-points, and she was rewarded with two new coaches. Emily proved to be kind-hearted, as she was the only engine concerned about Henry when he was ill due to leaky tubes and when she stuck up for Salty when Thomas and Percy were teasing him.
However, Emily has proven to be a nuisance on occasion as she bossed everyone about when they were clearing up after a storm; Thomas when taking passengers, and Percy when shunting the Troublesome Trucks. When pulling the Express for the first time, she was determined to keep to Gordon's timing, only to run out of water.
When Thomas had to stay at Knapford Sheds, Emily did not like his company at first as she just wanted some sleep. However, she learned how comfortable it is to have the company of friends and once Tidmouth Sheds was rebuilt, she was transferred there to be with her new shedmates.
Like most engines, Emily can get quite puffed up in the smokebox. When she was called "Excellent Emily", she ignored the advice of Murdoch, Thomas, and Duck only to get herself into trouble. Afterwards, she took their advice to get her job done.
Emily tries her best to make her friends happy. When she assumed that Mavis was sad, she took flowers to the quarry, but only created a mess. When she tried to help her friends with the football/soccer match, she neglected to fetch the dirty washing, which turned out to be the football/soccer team's uniforms. Also, when the Fat Controller lost his top hat, Emily went to find it without success and then took the special Christmas train without permission. However, she always makes amends for her friends' sake.
She later took Paxton to the Vicarstown Dieselworks after he was damaged during an accident at the Blue Mountain Quarry.
When Thomas hid his snowplow, Emily had to do Thomas' work and saved him when he got stuck in the snow again, even when he finds Thomas' snowplow.
Thomas told Emily about the "Flatbeds of Fear", but Emily did not believe in it and said there was an explanation. She eventually believed in it, until Thomas told her that it was just one of Salty's tall tales. When the Steam Team tried to clear the tracks of snow for Connor to deliver the last train for Christmas, Emily was unable to clear them from the Sodor side, but was happy to see Hiro as he cleared it from the other direction, then was disappointed when they mistook Harold for Father Christmas by believing his red port lamp to be Rudolph's nose.
She was later informed by Paxton about the rumor that Toby was to be scrapped, but Henrietta overheard and knew it wasn't true. Emily took her to find Toby, and once they found him safe, Emily gave him some of her coal. When Henry confided in Emily that he feared catching chicken pox from Stephen and Bridget Hatt, she assured him that he could not get chicken pox, joking that he worries too much. She became fascinated with Caitlin being able to go at such high speeds and wondered what it would be like to be fast, becoming depressed when she could not do so. However, in the end, she managed to save Caitlin when she descended down a steep hill with broken brakes.
When Thomas was fed up with Diesel's selfishness during the holidays, Emily partook in his plan to mend the Diesel's ways, much to her joy and amusement. She later attended the Earl's Christmas lunch with several other engines, including Thomas and a reformed Diesel.
Emily went with the other Sodor engines to be part of the Great Railway Show, competing in the Best Decorated Engine Parade along with James, Carlos, Rajiv, and Yong Bao, but she and James lost to Rajiv, Then she asked Ashima what event she was in, and Ashima told her that she was competing in the shunting competition, the same race event as Thomas.
Emily is based on a GNR Stirling Single tender engine.
Emily is painted in an emerald green livery with gold lining. From ”Emily to the Rescue” onwards, Emily has the number 12 in the middle square on each side of her tender in yellow with chocolate brown borders.
Thomas & Friends
- Series 7 - Emily's New Coaches, What's the Matter with Henry?, Salty's Stormy Tale, Something Fishy (cameo), Peace and Quiet (cameo), Bulgy Rides Again and Gordon and Spencer (cameo)
- Series 8 - James Gets a New Coat (does not speak), Thomas, Emily and the Snowplough, Don't Tell Thomas, Emily's New Route, Gordon Takes Charge (cameo), Spic and Span, Thomas and the Circus (cameo), Thomas Gets it Right (cameo), As Good as Gordon, Emily's Adventure, Halloween, Chickens to School, James Goes Too Far (cameo) and Percy and the Magic Carpet (cameo)
- Series 9 - Thomas and the Rainbow (cameo), Thomas' Milkshake Muddle, Molly's Special Special, Respect for Gordon, Thomas and the Birthday Picnic, Thomas and the Toy Shop (does not speak), Thomas and the New Engine, Toby Feels Left Out (does not speak), Thomas Tries His Best (cameo), Thomas and the Statue, Henry and the Flagpole (cameo), Emily Knows Best, Thomas' Day Off (cameo), Bold and Brave (cameo), Thomas and the Golden Eagle (does not speak), Keeping up with James (cameo) and Flour Power (cameo)
- Series 10 - Percy and the Funfair, The Green Controller (cameo), It's Good to be Gordon (cameo), Edward Strikes Out, Thomas and the Shooting Star (cameo), Big Strong Henry, Sticky Toffee Thomas (cameo), Thomas' Frosty Friend, Emily and the Special Coaches, Thomas and the Colours (cameo), Thomas and the Treasure and James the Second Best (does not speak)
- Series 11 - Thomas and the Storyteller, Emily's Rubbish, Dream On, Dirty Work, Gordon and the Engineer(does not speak), Thomas and the Spaceship (cameo), Henry's Lucky Day (cameo), Thomas and the Lighthouse, Thomas Sets Sail, Don't be Silly, Billy (cameo), Edward and the Mail and Thomas in Trouble
- Series 12 - Thomas and the Billboard, Steady Eddie (does not speak), Rosie's Funfair Special, Henry Gets it Wrong, Heave Ho Thomas! (cameo), Toby's Special Surprise, Excellent Emily, Saved You! (cameo), Thomas Puts the Brakes On and Percy and the Bandstand (stock footage cameo)
- Series 13 - The Lion of Sodor (cameo), Tickled Pink, Time For a Story (cameo), Percy's Parcel (cameo), Toby's New Whistle, A Blooming Mess, Thomas and the Runaway Kite, Steamy Sodor (cameo), Splish Splash Splosh, The Biggest Present of All, Snow Tracks, Henry's Good Deeds (cameo), Buzzy Bees (cameo) and Hiro Helps Out (cameo)
- Series 14 - Thomas' Tall Friend (cameo), Pingy Pongy Pick Up, Toby and the Whistling Woods (cameo), Henry's Health and Safety (cameo), Pop Goes Thomas (does not speak), Victor Says Yes, Thomas in Charge (cameo), Merry Winter Wish (cameo), Thomas' Crazy Day (cameo), Thomas and Scruff (cameo), Jitters and Japes (faceless portrait cameo) and Henry's Magic Box (does not speak)
- Series 15 - Emily and Dash, Percy's New Friends, Edward the Hero (cameo), Up, Up and Away! (cameo), Surprise, Surprise (cameo), Spencer the Grand (cameo), Kevin the Steamie, Percy the Snowman (cameo), Tree Trouble (cameo) and Fiery Flynn (cameo)
- Series 16 - Race to the Rescue (cameo), Ol' Wheezy Wobbles (cameo), Express Coming Through (cameo), Percy and the Monster of Brendam (cameo), Ho Ho Snowman, Flash Bang Wallop! (cameo), Thomas and the Rubbish Train, Bust My Buffers! (cameo), Thomas and the Sounds of Sodor, Salty's Surprise (cameo), Emily's Winter Party Special, Muddy Matters, Whiff's Wish and Happy Birthday Sir! (cameo)
- Series 17 - Wayward Winston, Calm Down Caitlin (cameo), The Lost Puff (cameo), The Phantom Express (cameo), No Snow for Thomas, The Missing Christmas Decorations, The Frozen Turntable (does not speak), Gone Fishing (cameo), The Afternoon Tea Express (does not speak), The Smelly Kipper and Thomas' Shortcut (cameo)
- Series 18 - Old Reliable Edward, Flatbeds of Fear, Signals Crossed (cameo), Duck in the Water (cameo), Duck and the Slip Coaches, Duncan and the Grumpy Passenger (cameo), Missing Gator (cameo), Spencer's VIP, Last Train for Christmas, Duncan the Humbug (cameo), The Perfect Gift (cameo) and Emily Saves the World
- Series 19 - Who's Geoffrey? (cameo), The Truth About Toby, Lost Property (cameo), Henry Spots Trouble, Snow Place Like Home, The Beast of Sodor, Toad and the Whale (cameo), Very Important Sheep (cameo), Salty All at Sea (cameo), Helping Hiro (cameo), Slow Stephen (cameo), Best Engine Ever, The Little Engine Who Raced Ahead, Philip to the Rescue, Diesel's Ghostly Christmas, The Other Side of the Mountain, No Help at All (mentioned) and Goodbye Fat Controller
- Series 20 - Sidney Sings (cameo), Toby's New Friend (cameo), Henry Gets the Express, Diesel and the Ducklings, Bradford the Brake Van, Pouty James, Letters to Santa (cameo), The Railcar and the Coaches (cameo), All in Vain, Henry in the Dark, The Missing Breakdown Train (cameo), Three Steam Engines Gruff, Engine of the Future, Hugo and the Airship and The Christmas Coffeepot (cameo)
- Series 21 - Dowager Hatt's Busy Day, Stuck in Gear, P.A. Problems, Cranky at the End of the Line, New Crane on the Dock, Philip's Number (cameo), The Fastest Red Engine on Sodor, A Shed for Edward, The Big Freeze and Emily in the Middle
- Series 22 - Forever and Ever, Confusion Without Delay, Trusty Trunky (does not speak; fantasy), What Rebecca Does, An Engine of Many Colours (fantasy), School of Duck, Seeing is Believing, Samson and the Fireworks, Cyclone Thomas (life lesson), Thomas' Animal Ark, Rosie is Red (cameo) and Counting on Nia (cameo)
- Series 23 - Chucklesome Trucks, Steam Team to the Rescue!, Panicky Percy, First Day on Sodor! (life lesson; cameo) and Rangers of the Rails
- Series 24 - A New Arrival, World of Tomorrow, Thomas and the Royal Engine, Emily's Best Friend, Thomas' Fuzzy Friend, Emily to the Rescue, James the Super Engine (cameo), The Inventor's Spectacular Bridge, Gordon and Rebecca, Coming Through! and Nia's Bright Idea
- Other - Thomas & Friends in 4-D: Bubbling Boilers
- 2005 - Calling All Engines!
- 2008 - The Great Discovery
- 2009 - Hero of the Rails
- 2010 - Misty Island Rescue
- 2011 - Day of the Diesels
- 2012 - Blue Mountain Mystery
- 2013 - King of the Railway
- 2014 - Tale of the Brave
- 2015 - Sodor's Legend of the Lost Treasure
- 2016 - The Great Race
- 2017 - Journey Beyond Sodor
- 2018 - Big World! Big Adventures!
- Series 7 - Five New Engines in the Shed, Salty and The Whistle Song
- Series 8 - Sounds, Emily, Surprises, A World Around You, Determination, Patience and Engine Roll Call
- Calling All Engines! - Busy, Trying,Together, New Engine Roll Call and The Dream Song
- Series 9 - Buffer Up and Share, Brave, Day and Night, Party Time, Pride and Every Day's a Special Day on Sodor
- Jack and the Sodor Construction Company - The Work Song and One Friendly Family
- Series 10 - Doing it Right, Favourite Place, Navigation, There's Always Something New, Responsibility, Strength and Engine Roll Call (Rock 'n' Roll version)
- Series 11 - Engine Roll Call
- The Great Discovery - There's a Job for Everyone, Where, oh Where is Thomas?, Engine Roll Call and Thomas, You're the Leader
- Series 12 - Engine Roll Call
- Hero of the Rails - Go, Go Thomas
- Series 13 - Roll Along, Thomas, You're the Leader, Determination and Engine Roll Call
- Series 14 - All You Need, Sir Topham Hatt and Engine Roll Call
- Day of the Diesels - Day of the Diesels
- Series 15 - Hear the Engines Coming
- Blue Mountain Mystery - Blue Mountain Mystery
- Series 16 - Thomas and Percy and Go, Go Thomas
- King of the Railway - Working Together Again and It's Gonna be a Great Day
- Series 17 - Hey, Hey Thomas! and On a Journey Today
- Tale of the Brave - Monsters Everywhere
- Series 18 - It's Christmas Time and The Best Friends Express
- Thomas' YouTube World Tour - A World Around You, Down by the Docks, Navigation, It's Great to be an Engine, Thomas' Anthem, The Whistle Song, Night Train and Rules and Regulations
- Series 19 - There's Snow Place Like Home, Race with You, Spring is Here! and Engine Roll Call
- Sodor's Legend of the Lost Treasure - We Make a Team Together
- Series 20 - Glynn's Christmas Wish, James the Really Splendid Engine and Accidents Will Happen
- The Great Race - Will You Won't You and Be Who You Are, and Go Far
- Journey Beyond Sodor - I Want to Go Home (cameo) and The Most Important Thing is Being Friends
- Series 21 - Set Friendship in Motion, Doing it Right and Trying
- Big World! Big Adventures! - Where in the World is Thomas? and We're Friends
- Series 22 - Set Friendship in Motion, Engine Roll Call, All the Girls Around the World, The Steam Team and Let's Dream
- Series 8 - Sounds (cameo), How Does Emily Get to the Station?, Being on Time, What Makes Percy Feel Better? (cameo), Edward Helps Emily Up Gordon's Hill, Surprise Destination, Which Way Should Thomas and Emily Go?, Dot to Dot - Emily and Guess the Engine - Emily
- Series 9 - Same Colour (stock footage cameo), Emily Respects, Who's Under the Coal Dust? - James and Getting to the Washdown
- Series 10 - Help From Your Friends, Who's Under the Coal Dust? - Emily, Mavis is a Steam Engine, Emily Huffs Out of the Station and Emily's Favourite Place
- Teresa Gallagher (UK; Hero of the Rails onwards; excluding Thomas and Friends in 4-D: Bubbling Boilers and The Great Race singing voice)
- Jules de Jongh (US; Hero of the Rails onwards, UK; Thomas and Friends in 4-D: Bubbling Boilers and The Great Race singing voice only)
- Blanche Ravalec (France and French speaking Canada; seventh series onwards)
- Yuka Shioyama (Japan; seventh and eighth series)
- Erina Yamazaki (Japan; Calling All Engines! onwards)
- Marit Berg (Norway; Hero of the Rails - seventeenth series, excluding Day of the Diesels, Blue Mountain Mystery and King of the Railway)
- Marianne Westby (Norway; Day of the Diesels - Tale of the Brave, excluding the fifteenth - seventeenth series)
- TBA (Norway; eighteenth series onwards)
- Chiara Gioncardi (Italy)
- Diana Pérez (Latin America; Hero of the Rails onwards)
- Marjolein Algera (The Netherlands)
- Kristina von Weltzien (Germany)
- Judy Winter (Germany; Audio Books only)
- Joanna Pach (Poland; Hero of the Rails onwards)
- Mia Kadosh (Israel)
- Kate Kelly (Brazil)
- María Sánchez (Spain)
- Susa Saukko (Finland; Hero of the Rails onwards)
- Ioana Perneș (Romania)
- Thanh Hống (Vietnam)
- Haffner Aniko (Hungary)
- Olga Kuznetsova (Russia)
- Kim Eun-a (South Korea)
- Elain Llwyd (Wales)
- Vina Papadopoulou (Greece)
- Michael Angelis, Pierce Brosnan and Teresa Gallagher all give Emily a Scottish accent reflecting the origin of her designer.
- One of Emily's models was on display in Canada at Nitrogen Studios, it is now part of the touring Thomas and Friends: Explore the Rails exhibit.
- Emily is the first character besides Thomas himself to say his phrase, "Cinders and ashes!", which was done in the thirteenth series episode, Tickled Pink.
- Some literary articles show her being sisterly mostly to Thomas and James. According to a magazine bio, she has a particular fondness for James and treats him like a little brother. In Railway Rhymes, the author states that Emily and Thomas act like brother and sister.
- According to Emily's Slide Show, she was built around the same time as Donald and Douglas.
- Emily's seventh series whistle sound would later be re-used for Peter Sam and Freddie.
- It was also used in the Mr. Men Show episode "Parks".
- Before Big World! Big Adventures!, Emily was the only member of the Steam Team not created by Wilbert Awdry, as well as the only female member up until the debuts of Nia and Rebecca and the only member (along with Nia and Rebecca) who was not introduced in the first series, also being its newest member until Nia's debut. Prior to Series 24, she was also the only member to not have a number, both before and after the addition of Nia and Rebecca.
- Emily is the only female member of the Steam Team to be introduced before the switch to full CGI. She is also the only female member to not have any nameplates.
- Prior to Series 23, she was the only Steam Team member without black buffers, which was seen as a goof in Chucklesome Trucks.
- According to Robert Gauld-Galliers's concept art, Emily was originally going to have handrails on top of her smokebox, three front coupling chains and a gold builder's plate on her wheel arch.
- Emily was called Emilie in the French dub of the seventh series.
- Emily is the second engine in the series originally without a number to later gain one. The first was Rosie.
- Emily is the first steam engine in the series to have only two driving wheels.
- Prior to the introduction of Nia, Emily was the only Steam Team member to not speak in a British accent in the UK dub.
- Emily has gone through a few aesthetic changes throughout the television series:
- Series 8:
- Her buffers had changed to silver as opposed to their original bronze color from series 7.
- Series 12:
- Her face became ever so slightly bigger.
- Series 23:
- She gained rivets on her buffer beam, smokebox front and sides, pistons, on her coupling hook and buffer bases, as well the lower part of her running board.
- She now has bronze handrails going from her smokebox to her cab.
- Series 24:
- She gains the number 12 on her tender.
- Series 8: