In The Roaring Twenties, when fashion was in a big upheaval compared to the decades before, Coco Chanel came up with a dress that would work in any evening or formal occasion, and blend in through any decade since. In short, she made the Ninja of dresses.
The Little Black Dress is pretty much what the name implies: a dress that is black and is little (although it can have a full length skirt). It usually comes without decorations, but can still have some trimmings as long as they are sparse and don't risk dating the dress.
The exact style can vary, working with many types of necklines and skirts, although since The Sixties, shorter skirts are more common.
This versatility and ability to work with any shot made the dress immensely popular with Hollywood costume designers, which spread the dress's popularity around the world.
Despite how it seems, this isn't really the opposite of a Pimped-Out Dress (and may rarely even overlap with Happy Holidays Dress). It's just the pimping out is rare, to a lesser degree, and still done in a way that makes the dress last.
But not every style of this dress is guaranteed to last. Many such dresses from The Eighties are more likely to be an Outdated Outfit.
Compare Lady in Red, Woman in White, Princesses Prefer Pink, Fairytale Wedding Dress.
Contrast Fashion Dissonance, I Was Quite A Fashion Victim.
Not to be confused with Woman in Black (although they can overlap), Launcher of a Thousand Ships (the shipping trope formerly named this).
Akari from 3-gatsu no Lion wears black dresses with full-lengthed skirt as part of her "uniform" while working at Mikako's Ginza bar.
In the manga of Soul Eater, BJ comes to Death City to find the spy or mole (rather than the anime version, where he came to help build a Magic Tool). One of the people he needs to investigate is Marie Mjolnir, his Christmas Cake ex-girlfriend. She shows up to the interrogation in a slinky Little Black Dress, which has about the desired effect.
Double Subversion in True Lies. When told to "dress sexy", Helen puts on one...with huge frills that seriously date it. Then she looks really hard in a mirror and rips the frills off as part of her impromptu self-makeover. Now we're talkin'.
Angela in Angel-A wore one, looked ridiculously good in it
Audrey Hepburn's little black dress in Sabrina. It was actually designed by Hubert de Givenchy, but in a power grab, Paramount costume designer Edith Head took credit for all of the clothes worn in the film.
There's an actual publishing company, specialising in Chick Lit, called Little Black Dress Books. Including this trope in some form is probably a contractual obligation.
Used as a metaphor in Al Franken's The Truth (with jokes). Al quotes a blogger who referred to the 9/11 attacks as "Bush'sLittle Black Dress" — just as the dress can be slipped on for any social occasion, the 9/11 attacks could be used as the justification for any policy he wanted to pursue.
Nicci of the Sword of Truth wears one of these all the time. It's symbolic of her unfeelingness and becomes associated with her being "Death's Mistress". In fact, when she's worried she might be recognized when she doesn't want to be, she wears a red dress and relies on her... assets to distract.
In the premiere of Buffy the Vampire Slayer, Buffy is shown holding up dresses in front of her to decide what to wear to the Bronze. Her comment on the black dress is "Hi, I'm an enormous slut!" Sure enough Buffy wears a little black dress while doing her notorious Mating Dance with Xander the following year.
Sarah Walker on Chuck wore more than her fair share both in the show, on the DVD covers, and in promotional material. Being played by Yvonne Strahovski, she wore them quite well.
The first collection of the Barbie Basics was focused entirely on this, all the twelve dolls wearing some interpretation of the little balck dress, with fashion packs consisting only on accesories, in order to adapt the dresses to different situations.
She was a long cool woman in a black dress...
"Oh, baby, you're a classic, like a little black dress..." - Fall Out Boy, Tiffany Blews
"Gettin' You Home (The Black Dress Song)" by Chris Young makes use of this trope.
In the music video of Selena Gomez's "Round and Round", she wears a black dress under her trenchcoat.
In the chalga song, "Moqt nomer" by Teodora & DJ Jerry "Little black dress next the skin / and hot body underneath"
The second verse of "Since You Brought It Up" by James Otto:
A female Commander Shepard can wear two over the course of the Mass Effect series:
In Mass Effect 2, Commander Shepard gets a leather one that squeaks in Kasumi Goto's Loyalty Mission. Once finished, the dress becomes available as casual wear aboard the Normandy.
Mass Effect 3 offers a spaghetti strap little black dress as part of her casual wardrobe. This one even includes her N7 logo.
Rayne in Blood Rayne 2 begins the game in a black evening gown. Floor length with long slits up the sides and Absolute Cleavage; the little fabric remaining is thin enough to cling skin-tight.
Carmelita Fox from Sly Cooper has one that she wears when not suffering from Limited Wardrobe syndrome, most noticeably in the second game when attending a lavish party, and during the ending cutscene of the third game.
In El Goonish Shive, during the Grace's Birthday arc, Nanase gives Ellen a little black dress to wear. It's the first time Ellen, an Opposite-Sex Clone of Elliot, has ever worn anything remotely feminine, and she's quite embarrassed by the ordeal.
While usually not her style, in Angry Joe's second episode of "Hotel Awesome", The Nostalgia Chick wore a cleavage-happy, nicely fitting black dress to flirt with him. Actually... [[Manipulative Bitch ...to lull him into cleaning her toilet.
Kim Possible wore one of these in "Emotion Sickness", to show that she's feeling a bit saucy towards Ron. It has since become a cornerstone in the show's fandom, eventually earning the Fan Nickname "The LBD".
Frankie from Foster's Home for Imaginary Friends wore the LBD in three episodes for separate occasions: a dinner date ("Frankie My Dear"), a red-carpet movie premiere alongside Mac ("Ticket to Rod", although neither of them actually end up going) and a fund-raising party ("Fools and Regulations").
Also worn by Drew Saturday in The Secret Saturdays episode "Guess Who's Going To Be Dinner" when she and Doc go on an anniversary date.
As of the website's first update in over a year and a half, Ruby Gloom's heavily-expanded wardrobe (which originally consisted of a medium-sized black dress, which actually seems to have been pushed out of the picture entirely) includes such a dress.