Multi Fandom Archives

A list of "Notable" Fan Fiction Archives. The only requirement to be on this list is that it covers more than one fandom. Single Fandom Archives, naturally enough, go on Single Fandom Archives.

Examples of Multi Fandom Archives include:

Archive of Our Own is a large fanfiction archive for all fandoms. Image embedding is allowed for fanart, audio embedding is allowed for podfics, and all fic can be downloaded in PDF, ePub, MOBI, and HTML format. In 2019 the entire site won a Hugo Award for "Best Related Work".
Fanfiction.net is the single largest repository of fanfic on the internet. Period. (Did the name tip you off?) However it is infamous for aggressively enforcing a soft "R" rating on stories posted there, abrupt (and borderline hostile) rule and policy changes, disabling links away from the site (save for in a few narrow locations), slow response to accusations of Plagiarism, and for permanently deleting fics without warning often with little to no justification.
FicWad Like Fanfiction.net, but much, much smaller.
Lunaescence Archives a moderated Anime, Manga, and Gaming Fan Fiction archive dedicated to quality.
Mediaminer.org, anime fanfiction and fanart. Early in its history Mediaminer had a cavalier attitude about other people's copyrights, and on more than one occasion was caught scraping other sites without permission to bolster its own content. Which means it might be worth searching if you're looking for an obscure, hard to find story from the late 1990s or early 2000s -- they just might have hoovered up a copy at one time.
Mibba is a bit like a Myspace-style writing site. They cover pretty much any fandom, you just have to search (although bandfic reigns supreme), and original fiction is available there too.
Passion & Perfection the Femmeslash fanfiction archive.
Superstories covers all superhero/heroine works, including original characters and settings. Once the premier NSFW superhero archive in the late 90's and early 2000's (the vast majority is porn), it went through several permutations and domain ownership/management changes, sometime "losing" previous stories and features, or replacing them with new ones; it now^[when?] seems on the verge of abandonment, with little forum activity, hosted sites/subdomains that vanished with all their content, and inaccessible story archives. The Choose Your Own Adventure / Round Robin feature called "Superstories Addventure" is the only part of the site still reasonably active.
Skyehawke, a multifandom archive that allows NC-17, and which attempts to screen out badly written fics.
Anifanfiction despite the name, very pro fanfiction with a horde of members, RPs, fanfiction and original fiction.
Twisting the Hellmouth was originally a site dedicated exclusively to Buffy the Vampire Slayer fics and crossovers with Buffy, but has, over the years, expanded its remit to become a general multi-fandom site with a distinct emphasis on BtVS. Among other features it is home to The Teraverse.
Wattpad, a mix of reading app and social network for writers. While a good amount of the user-created content bents towards original works, there is a notorious amount of fanfiction mixed within.
The rec.arts.anime.creative archive is the granddaddy of the anime-related fanfic and fanart archives, old enough to have the plain-text stories compressed to save bandwidth. It hasn't been updated in years, and the original is long gone, but Eyrie Productions, Unlimited still has a working mirror. Re-visit the days when Pokémon was new and Bubblegum Crisis was popular... if you dare.

Defunct Archives

The following sites were active when they were first added to this page but have since gone dark. The Wayback Machine made its own archives of them, and there may still be readable content to be found.

Fonts of Wisdom Fonts of Wisdom has archives of Buffy the Vampire Slayer, X-Men, and DC/Vertigo.
Insane Musings This pair had a bunch of hilarious fan fics involving X-Men, Sailor Moon, One Piece, Pokemon, Detective Conan, Buffy and many other different genres.