Toon Town

Cartoons are not real. They're made with art supplies and brought to life by animators and Voice Actors. It's sad but it's true.

Back when the world was a ball of ferns, when a good front lawn was a half-acre of bubbling slime, a giant amoeba split in two. The front half, the end with the brains, called itself Los Angeles. The butt end became Toon Town.

—Eddie Valiant, Who Censored Roger Rabbit? (Literature)

Hey, wait a minute! We seem to have made a wrong turn at Albu-coiky! Now we're in Toon Town, that very special district of Fantasy Land where cartoon characters are people, just like you and me. Sometimes, they exist as a separate and independent species, and sometimes, the place itself transforms humans into Toons. But all details aside, Toon Town is a loony sort of place where Cartoon Physics and the Rule of Funny reign supreme. Expect the Roger Rabbit Effect almost every time.

Not to be confused with the MMORPG, Toontown Online.

Examples of Toon Town include:

Anime

The Toon World, a deck of cards from Yu-Gi-Oh created by Pegasus and featuring caricatured duel monsters.

Comic Books

The DC Universe Earth-C, inhabited by Captain Carrot and His Amazing Zoo Crew.

Film

The Trope Namer from Who Framed Roger Rabbit, a suburban Los Angeles district where the Toon community lives. Quite crapsaccharine.
The world inside the painting in Mary Poppins, wherein the famous "Supercalifragilisticexpialidocious" musical number is set.
Cool World - The eponymous Alternate Universe inhabited by animated Doodles.
According to Space Jam, the Looney Tunes characters live in an alternate world that can be reached from an underground portal in the center of the Earth.
In Twilight Zone the Movie, during "The Good Life" segment, Anthony uses his powers to send his "sister" Ethel into the cartoon world, where she's chased around for a moment before being eaten. In this case, though, Toontown exists because of Anthony's dark powers.

Literature

Toon Town is casually mentioned, but not visited, in Who Censored Roger Rabbit? (Literature)? by Gary Wolf.
- Who Plugged Roger Rabbit? (a sequel to the film), on the other hand, spends quite a bit of time there.
The Doctor Who novel The Crooked World features a Deconstruction of this idea.

Live Action TV

The Halloween Special of Out of Jimmys Head briefly sends Jimmy and Golly into a cartoon world made of Milt Appleday's childhood drawings.

Theme Parks

The official mythos of the Disney Theme Parks states that the costumed characters are the real characters. Then there's Mickey's Toon Town and Roger Rabbit's Car Toon Spin.
Toon Lagoon in Universal Studios' Islands of Adventure can be seen as an example of this.

Web Comics

Zebra Girl takes this to it's natural extreme, with an entire alternate universe with cartoon characters whose lives and personalities run parallel with those of the people of the main universe.
Cartoon Land from The Cartoon Chronicles of Conroy Cat.
Love Me Nice takes place in a Who Framed Roger Rabbit setting with the Serial Numbers Filed Off. Mention is made of "Inkblot Grove" and the "Toon Quarter", but they haven't been visited in-comic yet; although they're implied to be more like toon ghettos.

Video Games

Toontown Online, a MMORPG inspired by the Trope Namer.
The Toon World from the very meta Game Cube title, Go! Go! Hypergrind!
The Cartoon Wasteland from Epic Mickey, home to neglected and forgotten Disney characters.
- Epic Mickey also brings us the hub map of OsTown, which is based on the theme park version of the trope and is sort of a more blatant example, though there's still some pretty grim stuff in the area.
  - Close inspection of the town sign reveals that the name originally was Toontown before Oswald took over and changed it.

Western Animation

Timmy of The Fairly Odd Parents sometimes goes into the comic book world of the Crimson Chin.
An episode of The Thirteen Ghosts of Scooby Doo sent Shaggy and Scooby into the worlds of several Newspaper Comics.
Cartoon Land, from the very early Walt Disney shorts, Alice in Cartoon Land.
Toontown was a rather important setting in Bonkers.
Cartoon Network has some advertisement about the channel being a big city, in fact.