|Hair||Moderate sapphire blue with moderate violet and Brilliant rose streaks|
|Skin||Pale, light grayish heliotrope|
|Voice||Tara Strong (speaking voice)|
Rebecca Shoichet (singing voice)
Twilight is a pony and human in the other world of Equestria. She has purple eyes, wears a light blue shirt and purple skirt with sparkle like her cutie marks in pony form and purple cold legs and Purple and pink legwarmers with black dress shoes. In the alternate world, she is turned into a teenage human and Spike into a dog. She can't get the hang of being human. Eventually, she meets the human versions of her Ponyville friends and manages to repair the friendships that Sunset Shimmer, who she finds out that everyone in the school in the human world is afraid of due to her meanness, had broken before Twilight arrived. Twilight decides to run against Sunset for Princess of the Fall Formal in order to get her crown back since Fluttershy had given it to the human version of Princess Celestia. She also develops a crush on Sunset's ex-boyfriend Flash Sentry.
Sunset tries many ways to stop Twilight from getting the crown, such as having the human versions of Snips and Snails record Twilight's difficulties coping with human varieties and turning it into a ridiculing video for all of the students to see. This turns Twilight into a laughing stock, but her new friends help turn her popularity around with a song, Equestria Girls. Sunset also has the Fall Formal decorations destroyed and the blame pinned on Twilight, nearly ruining her chances to get the crown back and return home. However, again with the help of Twilight's new best friends, as well as many students in the school, the auditorium is cleaned and redecorated in time for the dance.
At the Fall Formal, Twilight accepts Flash Sentry's offer to dance. She is voted the Fall Formal Princess, but when Snips and Snails capture Spike, she and her best friends chase the duo outside where Sunset Shimmer, in a last ditch effort to get the crown, threatens to destroy the portal leading to Equestria unless Twilight surrenders the crown. Twilight refuses, confident that Equestria can protect itself without the Elements of Harmony, but the evil unicorn-turned-human takes it by force and transforms into a demon, hypnotizing the students and teachers of the school to be her army. Twilight is nearly killed when Sunset Shimmer throws a fireball at her, but the magic crown, powered by her friendship with her gang, protects her and her best friends.
Twilight and her new friends manage to defeat the villainess with the power of friendship, and when Sunset Shimmer is reverted to her human form, she becomes remorseful, stating that she doesn't know where to begin with friendship since she's never had a friend. A forgiving Twilight has her new friends teach its magic to her. Principal Celestia gives Twilight her crown after she and the student body witnessed her true duty of being a princess, no matter which world she was from, can inspire others to stand with her.
After the dance, Twilight and Spike return to Equestria, Twilight feeling more confident about being a princess than before. She bumps into the pony version of Flash Sentry and blushes upon meeting him. Twilight's pony friends tease her for having a crush, but she denies it.
Twilight reappears when she is summoned back to Canterlot High School by the human versions of her friends from Equestria, now known as the band, The Rainbooms, and a now-reformed Sunset Shimmer, when three new girls to the school, known together as The Dazzlings, begin to spread hostility amongst the students before an upcoming Musical Showcase fundraiser being done by the school. Discovering them to actually be Equestrian sirens banished to the human world by the legendary Star Swirl the Bearded, Twilight hopes to stop them immediately at the party before the Showcase, now turned into a Battle of the Bands. While there, she bumps into Flash Sentry again, who is happy to see her since she left after the Fall Formal.
Unknown to Twilight, hostility amongst her human friends over minor things, like Rainbow Dash calling the Rainbooms "her" band, and Rarity and Applejack arguing over Rarity wanting the band to perform in style, are tainting the Equestrian magic of friendship she had left them with when she returned home after the Fall Formal events, rendering it unusable. Twilight is convinced instead that they need to create a counter-spell to sing at the Battle to undo the Dazzlings spell, but finds herself struggling with the pressure at wanting to help her friends out and stop the Dazzlings. She is even further disheartened when Flash Sentry, secretly under the Dazzlings' spell, declares her an enemy to him and his band since she joined the Rainbooms, leaving her in tears.
Although the Rainbooms are able to make it to the finals of the Battle, with a little manipulation of Principal Celestia and Vice Principal Luna by the Dazzlings after the semi-final round, they are trapped under the stage where the finals are to be held by Trixie Lulumoon and her band, The Illusions.
Twilight gives into despair as she believes the counter-spell never would have worked anyway, but soon realizes the truth once she sees Sunset gives the Rainbooms a good talking-to about how their petty issues were the reason the magic of friendship was not working. Twilight feels ashamed at having not seen the hostility amongst the Rainbooms sooner, but Sunset assures her that you don't need to do everything yourself and you can count on your friends to help you out.
Once Spike rescues her and the others with the aid of DJ Pon-3, whose headphones protected her from the Dazzlings' spell, Twilight leads the Rainbooms in confronting the Dazzlings while they were performing on stage and were on the verge of triumph.
Although the Rainbooms are able to put up a fierce fight, when the Dazzlings summon astral versions of their Equestrian selves, Twilight tries to attack Adagio Dazzle's astral self with a vocal attack, only for it to be deflected by Adagio's more powerful attack, which even pushes Twilight back several feet, but she holds her ground. Twilight, and the rest of the Rainbooms, are unable to withstand the follow-up attack by all three Dazzlings, and Twilight's microphone is knocked out of her hand and lands at Sunset's feet. With the Dazzlings closing in for the kill, Twilight calls out to Sunset for her aid, and Sunset's added help is able to give Twilight and the Rainbooms the additional power they need to fight off the Dazzlings and destroy both their astral selves and the ruby pendants that empower them, leaving the now tone deaf girls to be chased off-stage in disgrace by the furious students and faculty.
Flash Sentry, no longer under the Dazzlings' influence, then arrives to embrace Twilight, but before they could possibly kiss, Trixie breaks it up to vow revenge on the Rainbooms. Afterwards, Sunset takes over for Twilight in the Rainbooms as she and Spike return home to Equestria, promising to return now that the portal between Equestria and the human world could be reopened at any time.
It is implied that Twilight has her own human counterpart in the mirror world; the human Pinkie mentions seeing a girl who looks like her (and owns a dog named Spike) in the city.
The human counterpart of Twilight Sparkle makes a cameo in Rainbow Rocks, appearing in a bonus scene after the credits. She appears to be a scientist who has been researching the strange events going on in her city, with all evidence pointing to Canterlot High School as the source. If further Equestria Girls stories are made, her investigations will likely become a plot point.
When entering the human world, Twilight comes across as a typical socially-awkward and clumsy teenage girl who tries to fit in, which is due to her lack of knowledge of the human world. However, we see that she has her determination when she finds the crown, her studiousness when she leads the students to clean up and redecorate the gym for Fall Formal, and her kind heart when she rebuilds the broken friendships of the human versions of her friends in Ponyville caused by Sunset Shimmer. She also becomes very shy around Flash Sentry due to her crush on him, but manages to work up the confidence to accept his offer to dance with her.
Twilight Sparkle's Quotes
"My magic! It isn't working!"
"What does the rest of me look like?"
Twilight Sparkle: "Looks like if I want my crown back, I'll have to become Princess of the Canterlot High Fall Formal. So that's what I'm gonna do!"
Spike: "And how exactly do you plan on doing that?"
Twilight Sparkle: "'I have no idea!"
- Twilight deciding to run against Sunset to win back the Element of Magic, but having no plan on how to do it
"Now would be a good time to start."
"The crown maybe upon your head Sunset Shimmer. But you cannot wield it, because you do not possess the most powerful magic of all....the magic of friendship!"
"The magic of friendship doesn't just exist in Equestria. It's everywhere. You can seek it out, or you can forever be alone."
"I bet they can teach you."
"I know we have only been friends for a short time, but I am going to miss all of you so much."
"I think she's going to be fine. I left her in good hands."
"I can't believe all this tension was happening right under my nose and I didn't realize it. I'm supposed to be the one with all the answers. And all I've done since I got here is let you down."
(Twilight's mirror world counterpart, regarding her investigation into CHS) "No doubt about it, Spike. There's definitely something strange going on at that school..."