Fandoms listed are not exhaustive, the sites can have more than what's displayed here.
By default, English is assumed to be the main language of the sites and is thus not listed. Languages listed are on top of English unless precised otherwise.
The presence of a site in this list does not constitute endorsement of its content.
LeGaosaure's Archive: Fanfic and original fic, with some bits of French. There's a separate section for microfics (under 500 characters).
Hades, Library of Ruina, Limbus Company, Lobotomy Corporation, Love Live! Sunshine!!, Marvel Cinematic Universe, Original Work, Project Moon, The World Ends With You, Vampire : la Mascarade, Vampire: The Masquerade – BloodlinesFrench
enchantedsleeper's space: A home for fic, fanart, meta and miscellaneous writing by enchantedsleeper.
Rurouni Kenshin, Yu Yu Hakusho, Yu-Gi-Oh!, Katekyo Hitman Reborn!, Avengers Movieverse, The Strange Case of Starship Iris, Wooden Overcoats, FENCE, D&D: Honor Among Thieves
Bookscorpion's Lair: An archive of fanfics written by bookscorpion.
The Witcher (video games), Cyberpunk 2077, Mad Max, Shadowrun, Baldur's Gate 3, Discworld (others to follow)