Tomboyish Ponytail

Basically using a ponytail to set off girls who are Tomboys, Ladettes, or at least don't act in a "proper" girlish manner.

This is Truth in Television for many tomboys in Real Life, due to being an easy to do style that gets your hair out of the way. In fiction, odds are that if a girl is wearing a ponytail (save for one paired with an elegant hairstyle), she's not going to act demure or feminine, at least not all the time. Back when girls just didn't have boy hair, no matter what, ponytails were a way for tomboys to rebel against the curls their mothers wished they'd worn. At least this was the case in 60s-80s girl empowerment fiction.

Bonus points if she wears overalls or is a Rebellious Princess.

Keep in mind that since not all tomboys wear ponytails, and not all "feminine" girls avoid ponytails, there isn't much point in listing aversions to this.

Compare Slipknot Ponytail, Girlish Pigtails, Braids of Action, Boyish Short Hair, Tomboyish Sidetails.

Contrast Regal Ringlets, Princess Curls, Long Hair Is Feminine.

Examples of Tomboyish Ponytail include:

Anime and Manga

Makoto, aka Sailor Jupiter, of Sailor Moon.
Ukyou from Ranma ½ wears her waist length hair in a ponytail and still comes off as Bifauxnen.
- Ranma wore "her" long hair this way while training in China.
Sango in Inuyasha has her long hair bound in a ponytail when she's in her battle-garb. Otherwise she has it tied at the end with a ribbon.
Signum of Magical Girl Lyrical Nanoha, a stoic Magic Knight and generally one of the least feminine women on the show.
Kyoko Sakura of Puella Magi Madoka Magica. While her magical girl outfit isn't really tomboyish, she's the only character seen in causal clothes other than a school uniform (she wears a blue hoodie and shorts in most scenes).
Vietnam of Axis Powers Hetalia.
Misaki of Excel Saga.
Yui Goidou of The World God Only Knows after she goes Bifauxnen.
Presea from Magic Knight Rayearth. Also, tomboys Tarta and Hikaru have their hair in a braid. Contrast to the girlier girls Emeraude, Alcyone, Tatra, and Umi, who wear their hair down. Caldina, Fuu, and Aska are harder to classify, since they have both tomboy and girly girl traits, but all wear different hairstyles.
Asaka (AKA Neuroloid Girl) in Dokkoida
Bleach: Action Girl Yoruichi. She used to have short hair, but a hundred years spent mostly as a cat allowed her hair to grow out. Now she spends most of the time with it tied back in a ponytail while she kicks butt with the best of the men. Since her extremely high aristocratic rank wasn't quite high enough to be a Rebellious Princess, she also doubles as a Spirited Young Lady, too.

Comic Books

Young Justice: Quite obvious in the Tomboy and Girly Girl pair of sweet and demure Miss Martian, who wears her hair loose around her shoulders and brash Tsundere Artemis who wears hers in a tight ponytail at all times.
Betty Cooper from Archie Comics, as the Tomboy to Veronica's Girly Girl.

Fan Works

Rise of the Galeforces: Sarah Squall, aka Stratogale, has one.

Films

Laney of She's All That, to show how she's too weird to be pretty.
- Which got mercilessly mocked in Not Another Teen Movie.
Cady in Mean Girls before she joined the plastics.
- The plastics actually tell her that they have a rule about only wearing hair in a ponytail once a week.

Literature

Jenit Sulla in Ciaphas Cain, a Leeroy Jenkins female officer in the Imperial Guard.
Thursday Next.
- Also her Evil Twin Thursday Next-1, a Dark Action Girl who has a much more severe ponytail, held in place by a leather strap rather than a scrunchie. (Thursday Next-2 is a subversion, at least to start with; she's an Actual Pacifist Granola Girl whose scrunchie is made of hemp.)
Kate Whetherall from The Mysterious Benedict Society. Also Jillson, who ties her ponytail with wire.

Live-Action TV

Jo from The Facts of Life.
Kara Thrace from the rebooted Battlestar Galactica Reimagined, when her hair is long enough to be tied back.
Lois Lane often sported a Tomboyish Ponytail on Smallville.

Video Games

Lara Croft from Tomb Raider.
Hilda (Touko in the Japanese version), the female player character in Pokémon Black and White, has a huge, voluminous ponytail, complete with Hair Antennae. Her look gives off a convincing Tomboyish feel, and fan interpretation commonly presents her as One of the Boys/a Lad-ette.
Marle of Chrono Trigger.
Lip of Panel De Pon, also a Tomboy Princess.
Princess "Eva" Evangeline of the Kingdom of the Northern Reaches, poster girl for Dungeon Siege II, sports this look, as did her predecessor from the first game, officially known as Farm Girl.

Visual Novels

Mion of Higurashi no Naku Koro ni, but she is girly at heart.

Webcomics

Zii of Ménage à 3.
Kate of Rhapsodies (When she doesn't have it in a pencil studded bun.)

Web Original

Sasha Hunter of Greek Ninja.

Western Animation

Leela of Futurama.
Plum Pudding from Strawberry Shortcake's Berry Bitty Adventures.
Applejack's mane in My Little Pony Friendship Is Magic is styled like this, cementing her place as one of the tomboys in the main cast. It's also a "pony"tail.
- Megan from the original My Little Pony series wore her hair like this.
Bridgette of Total Drama Island.
Heloise on Jimmy Two-Shoes.
June of Ka Blam!.
Talon from Static Shock.
Artemis on Young Justice.
Avatar Korra combines the ponytail with Tomboyish Sidetails to show she is an Action Girl.