Token Lesbian

There's one woman (or girl) in the cast of characters who isn't like the others - she isn't interested in boys at all, but she isn't asexual, either. Since there's only one such character in the cast, she's the Token Lesbian.

This trope doesn't make any assumptions about the character's personality - she can be a Lipstick Lesbian, a Butch Lesbian, a Schoolgirl Lesbian, a Lesbian Jock, in a Transparent Closet, or she could be so well-developed as a character that it's impossible to pigeonhole her. The important part of the trope here is that she's a Token Minority, and the minority is "homosexual people".

Contrast with Everyone Is Gay and Hide Your Gays. Note that Token Yuri Girls is not a subtrope of this trope, because that trope discusses works with more than one lesbian character.

For the trope that used to be here about two lesbians being a couple in a work that's otherwise about gay males, see Token Lesbian Couple (which is also not a subtrope of this trope).

Anime and Manga

 * Azumanga Daioh: Kaorin, who's in a Transparent Closet. (When even the class cloudcuckoolander can figure it out, it isn't a secret.)
 * A Certain Scientific Railgun: Kuroko Shirai, who has Single-Target Sexuality aimed at her roommate (and the show's protagonist) Mikoto Misaka.
 * Kokoro Connect: Maiko Fujishima, the Class Representative for three of the show's five main characters. After her first appearance, her sexuality is rarely mentioned, although at one point she laments living in a culture where a couple is defined as a man and a woman.
 * Sanae Nagatsuki is a rather blatant Stalker with a Crush of the titular Squid Girl.
 * Taishō Baseball Girls has Tomoe Tsukubae, who joined the baseball team in order to be closer to the story's protagonist Koume Suzukawa.
 * The Other Wiki describes Ayako Yuuki as the "sole lesbian character" in Variable Geo.

Film

 * The 1929 film Fall On Your Knees has the character Countess Geschwitz, who is "often cited as cinema’s first explicit lesbian character".
 * Officer Specter in Onward is the first openly lesbian character in any Pixar movie.

Live-Action TV

 * Played with on Law & Order, when Serena Southerlyn was revealed to be lesbian immediately before being Put on a Bus. The Other Wiki says that "[t]he decision to announce Southerlyn's homosexuality only as the character left the show was widely denounced both by fans and critics."
 * Newscaster Bronwyn Jones on the 1995 series Muscle outed herself as a lesbian on-air in order to avoid blackmail. This being a mid-'90s comedy series, her sexual orientation was exploited by her employers.