Brainy Brunette

Stereotypically speaking, in fiction, blondes are lacking in intelligence, redheads are lacking in feminine charm, so, out of the trio, brunettes are all brain. Like the Dumb Blonde, the brunette varies quite a bit. They can bashfully hide behind their books or glasses, with their hair done in pigtails or a bun or they can boldly use their smarts for their ambitions. Whichever it is, their knowledge is real—if the Brainy Brunette is on your side, then you can always count on her smarts in a fix. She may be a Hot Librarian, a Hot Scientist, or even a Wrench Wench. If so, her Sesquipedalian Loquaciousness and/or Techno Babble will turn people on. And she always has nice, thick, brown locks. What they don't have is strength, like the Squishy Wizard (who may be The Smart Guy himself), as they care more about their mind than their body. That's what makes a Badass Bookworm so interesting, a rare combination.

This trope doesn't mean that blondes and redheads can't be the brains of the outfit. It's just more common for them to have brown hair, especially if they're female, though there are a couple of male examples.

Contrast Dumb Blonde and Fiery Redhead. And, as with both of them, this character can be either good or evil. Make the hair color extremely dark, though, and the character borders on Shiny Midnight Black (yet also brainy).

Examples of Brainy Brunette include:

Advertising

The Brown M&M seems to be this, with glasses and all.

Anime and Manga

Mazinger Z gives two examples with The Professor Gennosuke Yumi and his daughter, Sayaka. Although she is an Action Girl, she is pretty smart and knowledgeable.
Naruto gives us three male examples in Shikamaru, Neji, and Iruka.
Futari wa Pretty Cure gave us Honoka/Cure White.
Lita from Animerica, in contrast to the blonde Janine and red-headed Jessica. There's also Wendy, Ron's older sister, and his previous Love Interest, Yukina. Kasuse and Yusuke may count, as well as Maya, Lita's Cool Big Sis.
Yomiko Readman from Read or Die.
Vandread gives us Parfait, who is a Wrench Wench.
Sheska from Fullmetal Alchemist; an extreme bibliophile with a photographic memory of everything she reads.
Chao Lingshen and Satomi Hakase from Mahou Sensei Negima! Also, Yue and Nodoka, for a given value of "brunette".
Ouran High School Host Club: Haruhi Fujioka. Though nobody in the host club is truly unintelligent, Haruhi is book smart to the point of being occasionally portrayed as a nerd, and possesses more common sense than most of them. Not to mention that everybody is gay for Haruhi.
Yomi from Azumanga Daioh fits this trope nicely. Excluding Child Prodigy, Chiyo, she's easily the smartest member of the group (with the possible exception of Sakaki).
El Hazard's Afura Mann, the wind priestess of Mt. Moldune. She's portrayed as the most intellectual of the three and, in The Wanderers series, she has her very own library!
Insufferable Genius Seto Kaiba.
Hakkai from Saiyuki is the trademark smart-guy.
Light Yagami and L from Death Note.
Leo Regulus from Saint Seiya: The Lost Canvas, said and proven to be a battle genius.
Mizuno Ami from Sailor Moon.
Although the Kodomo no Jikan manga can't decide on Mimi and Rin's hair colors, the anime has decided Mimi is a brunette. What shade is still undecided.

Comic Books

Valerie from Josie and the Pussy Cats is a female MacGyver.
Lois Lane in Superman continuities where she's not a Fiery Redhead. And where she's actually brainy.
Kitty Pryde of X-Men.
- Also from the X-Men: Nobel Prize-winning geneticist Moira MacTaggert.
Marlene in Jet Dream, who's described as "Powerful as a wrestler, but with a cool, precise Teutonic mind."

Film

Belle from Disney's Beauty and the Beast.
Tiana from The Princess and the Frog. Naveen too, when he can be bothered to do stuff.
Queen Elinor from Brave.
Roxanne Ritchi from Megamind, so much that the title character (a Gadgeteer Genius) admits that she's the smartest person he knows. She's also voiced by brainy Tina Fey.
Edna Mode from The Incredibles.
In the film version of Starter for 10, the character of Rebecca is a brunette and intuitive. She holds various protests and is often seen informing the main character, Brian Jackson, of her ideas.
Evelyn in The Mummy. She's also a Hot Librarian.
Brutally mocked in Where The Truth Lies:

Lanny: My favorite catches were the intellectuals. They'd be the ones in the straight black dresses, severe black hair. Your basic neurotic, eyeglasses, cool jazz, liberal, "I'll fuck any black guy as part of my personal apology for racism in America" type.

- The person reading his letter then looks across the room and sees a bookish-looking brunette. And you automatically imagine her doing one thing and one thing only...
Jenny in An Education dreams of getting into Oxford, and she's got the brains to do it. She has a Foil in Dumb Blonde Helen.
Inverted in Jennifer's Body. The brunette Jennifer is a vapid Alpha Bitch (both before and after she is possessed), while the blonde Needy is a Hollywood Nerd, complete with the glasses.
Ariadne in Inception.
There's magazine writer Summer from Definitely Maybe.
Emma from No Strings Attached, who studied at MIT, is a doctor in Boston, and turned up to a pajama party in actual pajamas in her college days.

Literature

Hermione Granger from the Harry Potter book series is probably the embodiment of this trope in its purest form.
Lessa from Dragonriders of Pern qualifies as she is not only the one to figure out Threadfall patterns and trick a Dragonrider into challenging a Lord Holder to a death match, but she also figures out how to save the planet and then does it against the wishes of everyone else involved.
Tiffany Aching of the Discworld books, who read the dictionary for fun when she was a girl, always pestered traveling scholars with difficult questions, and turned out to be very clever and talented for a witch her age.
Jo March in Little Women has thick chestnut hair, "her one beauty", and is a devoted writer.
October "Toby" Daye in Rosemary And Rue is a tough and savvy private investigator who servers both mortal and faerie clients.
Amelia Marsh in Darkness Visible borders on the Shiny Midnight Black end of the spectrum and is very intelligent/educated for a woman of her era. She speaks French, paints beautifully, and, to Lewis's surprise, can play chess. Mrs Emiline Pound also counts, though her hair is going gray. It is her tireless work in the Warden's archives which finally reveals the identity of the traitor among them.
Claudia's sister Janine from Babysitters Club is an exaggeration with her Asian and Nerdy ways. Claudia feels bad when she compares herself to her genius sister.
Anji Kapoor, from the Doctor Who Eighth Doctor Adventures, is a genius or very close to it when it comes to economics, to the point of seeming to be a bit of a nerd when you get her started on the topic.
Averted in Percy Jackson: Athena, the goddess of wisdom, is blond and so are her descendants (they have Gray Eyes, though). Annabeth, the brains of the group around the titular character, is Athena's daughter.

Live-Action TV

Fred Burkle on Angel. She was adorable, sexy, funny, and her high intelligence was a great asset to the "Fang Gang".
Double Subverted with Cordelia in Buffy the Vampire Slayer where Cordelia was initially shown as an example of the Brainless Beauty. Though, after exams, it was revealed that she actually had very good grades which she simply chose to hide from her peers, thinking it would make her less popular.
Kaylee, the resident Wrench Wench on Firefly. She had very light brown hair, but it was still brown, and her mechanical genius was definitely a fetish for some.
- Also, River, who was a genius and a Waif Prophet, though she was also completely nuts.
  - Simon himself would count, with his fierce knowledge of medicine and ability to organize a heist in one episode.
- Inara may make her living with her body, but her brain is no slouch either. She has a working knowledge of many subjects that a Courtesan would be expected to converse intelligently about. She's well-versed in human psychology and the arts physical, martial arts, swordplay, history, religion, etc.
- Zoe is an expert on setting traps, organizing missions, and leading attacks, all of which were skills she picked up while serving in the military.
Summer Glau's other character, Bennett Halverson on Dollhouse, also qualifies.
- And yet again, as Orwell in The Cape (trope).
Liz Lemon on Thirty Rock. Emphasized by the fact that the show's two other female regulars are both Dumb Blondes. In fact, every character ever played by Tina Fey.
- The film Baby Mama paired Fey (no, not like that) with blonde Amy Poehler. Guess what their characters' personalities were.
Not quite as overt as the other examples, but Chuck in Pushing Daisies has a great general knowledge and speaks seemingly every language known to man.
Joey Potter on Dawson's Creek.
Rory Gilmore on Gilmore Girls.
Temperance Brennan, Bones. Place your own generic erection euphemism here, I just can't think of a good one.
- When you think of it, they're all brunettes.
Abby Sciuto of NCIS. Underneath her punk groupie looks, she's a scientist and Mensa member.
- Ziva is no slouch either, with her smart-ass comments, multiple languages, skill with weapons, and Photographic Memory.
Most of the brunettes in CSI: Crime Scene Investigation probably qualify; Sara Sidle definitely does.
- Carries over to CSI: NY and probably CSI: Miami as well. All the casts have several smart brunettes.
At least in the later seasons, Chloe O'Brian in 24.
Possible subversion in Privileged: Megan, the Yale graduate, is shown as a redhead; however, in the first episode, we're told that she dyed it red and we never really learn her natural colour, so it's possible she's simply a Brainy Brunette in disguise.
Blair on Gossip Girl.
Detective Kate Beckett from Castle.
Lindsay Weir on Freaks and Geeks.
Emily Prentiss from Criminal Minds. Her predecessor, Elle Greenaway, was also intelligent, but Emily gets more credit because she has yet to be dumb enough to kill someone in cold blood. Special Agent Doctor Spencer Reid also qualifies.
In Doctor Who, Zoe can blow up a computer with her brain. And Romana I is repeatedly shown to be smarter than the Doctor. Of course, Barbara was the very first brainy companion, being a history teacher. And let's not forget widely beloved Intrepid Reporter Sarah Jane Smith, who is repeatedly shown both on Doctor Who and The Sarah Jane Adventures to be quite intelligent, considering she saves the Earth roughly every week.
Annie Edison on Community.
Averted and played straight in No Ordinary Family. Stephanie is a world-class research scientist who graduated from MIT and is blonde. Her nerdy yet attractive sidekick Katie, also shown to be very intelligent, is a brunette.
George from Being Human (UK) is described as having a brain like a "planet" and is said by several characters to be able to carry a much more prestigious job than hospital janitor if he wanted.
Carrusel has Valeria, Carmen, and Alicia, to a lesser extent. All 3 girls have jet black hair and are good students. Valeria is a talented painter. Carmen is very good with people. And Alicia is very mature and has common sense.
Dr. Helen Magnus of Sanctuary, Omnidisciplinary Scientist extraordinaire, whose long brunette locks are a stark contrast to Amanda Tapping's former role as the short-haired, blonde, and equally brainy astrophysicist Major Samantha Carter on Stargate SG-1. This was probably deliberate.
The younger Dunphy daughter, Alex, on "Modern Family"

Theatre

Alpha Bitch Lucy from 13 is a brainy brunette who uses her brains for her own ends.

Video Games

Jennifer Willis, from the original Splatterhouse.
Miranda Lawson from Mass Effect 2 falls under Shiny Midnight Black.
The default player character from A Dance With Rogues has black hair and is really the only character who ever fits the role of The Smart Guy on your team.
Morrigan from Dragon Age, whose intellect is beyond question (though she does seem to spend a lot of it on thinking up more ways to insult Alistair).
Both April Ryan and Zoe Castillo from The Longest Journey series. And the Word of God is that the stereotype played (possibly without realization) a role in their design.
Angela Delvecchio of Backyard Sports.
Rita from Tales of Vesperia.
Ace Attorney has Lana Skye, Chief Prosecutor, and her younger sister, Ema, Police Detective.
Mei Ling and Naomi Hunter in Metal Gear Solid.
- Solid Snake (160-point IQ, speaks six languages) and Otacon (expert programmer, Gadgeteer Genius, creator of Metal Gear Rex) are male examples (although Otacon's hair is more gray-brown than conventional brunet).
Princess Zelda in her only remotely brunette incarnation, The Legend of Zelda Twilight Princess, is noted by her former tutor to have been an excellent student. She's also the chosen disciple of the Goddess of Wisdom, so it's only logical.
In Fire Emblem 4, Lana and her Expy Manna are kind, sensitive, and very intuitive White Magician Girls. Also Oifaye, who was The Strategist in the first part and then became the Big Brother Mentor to Celice's group.
In the second Dark Parables game, Cinderella is implied to have been this, based on the fact that her husband constructed a library in her memory.
Stern, the Material of Wisdom from the Magical Girl Lyrical Nanoha A's Portable. Unlike the light-haired Nanoha whose form she was based on, Stern's hair is dark brown.

Web Comics

Biologist Dr. Jean Poule in The Inexplicable Adventures of Bob.
Emily, from Our Little Adventure, is a straight example. Julie also has plenty of brains and brown hair, but it's apparently not her real hair color.
In the Remix Comic version of Jet Dream, Marlene is even brainier, described as one of the best people in the Western world at Doing Science.

Web Original

Parodied by The Nostalgia Chick, who thinks she knows everything but is really a Know-Nothing Know-It-All. Played straight by Ms. Exposition BBF Nella and Mad Scientist Dr. Block.
Laci Green, pint-sized sex guru from the west coast.
Thalia, Calliope, and the rest of the Muses in Thalia's Musings.
- Also, Athena, the Goddess of Wisdom, Crafting, and Battle Strategy.

Western Animation

Velma Dinkley of Scooby-Doo.
Jeanette Miller of the Chipettes.
Inverted on The Powerpuff Girls where the red-headed Blossom is the brainy one while the brunette Buttercup is the aggressive spitfire. (Bubbles is still the Dumb Blonde, though.)
Bushroot's Hot Scientist love interest Dr. Rhoda Dendron from his origin story on Darkwing Duck. Morgana the successful businesswoman and scholar counts as well.
Daria is a combination of this trope and Deadpan Snarker. It helps make her a famous Snark Knight.
- Daria's hair is actually a dark auburn red, but she is certainly brainy. A more straightforward example would be her artistic best friend Jane Lane, who is doubtlessly a brunette.
Wendy from South Park.
Yumi, from Code Lyoko.
Azula, from Avatar: The Last Airbender, is terrifyingly intelligent and a Manipulative Bastard par excellence. And Katara isn't dumb, either, though her brother Sokka is "the Idea Guy" of the Gaang. Of course, all but one character in the show are or were dark-haired.
Total Drama Island has Noah (book smarts), Courtney (legal smarts), and Alejandro (mechanical smarts).
Played mostly straight with the Kanker sisters in Ed, Edd 'n' Eddy. May (the blonde) is Too Dumb to Live; Lee (the redhead) definitely has the attitude; and while Marie has blue hair and isn't overtly bookish, she comes up with the smartest ideas.
The Simpsons: an episode's B-plot focused on Lisa joining the debate team and ending up dyeing her hair brown to prove that they didn't take her seriously before, due to being blonde.
On Recess, Gretchen and Spinelli invert their typical hair tropes, as Spinelli (brunette) is firey and Gretchen (redhead) is brainy. Gretchen did have black hair in the pilot, though.
- T.J. subverts this, as he's quite ditzy when it comes to academics, but is a genius when it comes to his schemes on the playground.
- Miss Grotke plays this trope straight.

Real Life

Tina Fey counts.^[context?]
Natalie Portman, anyone?^[context?]
Danica McKellar, math genius.
Marilyn vos Savant, listed in the Guinness Book of World Records (at least, at one point) as having the world's highest IQ.
Due to ethnic traits, Asian and Nerdy has almost total crossover with this.
Hedy Lamarr, actress and inventor. Also major-league hottie.
Elliot Page. There's really no need to explain this one.^[context?]
Audrey Hepburn didn't have much in the way of formal schooling, but she was extremely well-read, could speak at least seven languages fluently, and was a talented piano player.
Elaine May.^[context?]
Nino Burjanadze, a political leader in the Republic of Georgia.
Emma Watson is a graduate of Brown University and is rumored to have had grades rivaling Hermione Granger's - the icing to the cake is that she considers her education more important than her acting career.