A Period Fic usually takes the characters of any fandom and places them in a different time period than the setting of the story. It may involve time travel, but most of the time it doesn't.
May or may not include the Used Future.
- Blood of Beauty takes Sonic the Hedgehog into 1880s American, turns several characters into vampires, and dabs in Paranormal Romance.
- Rendezvous With Fate by iCe relocates Ranma ½ to feudal Japan, and casts Akane as the time-traveling widow of Ryouga, who has accidentally come back in time and possessed the body of Ranma's estranged wife, Kodachi.
- Golden Day by Gondolier moves the plot of The Phantom of the Opera to Hollywood in the Roaring Twenties — with good period research, no less.
- There was once a sudden explosion of Cartman/Kyle South Park fics set in Nazi Germany, with Kyle in a concentration camp, hiding in Stan's family's attic, or otherwise persecuted, and Cartman as a sadistic Hitler Youth.
- Scion: The Last Aeromancer is a story on Fan Fiction Dot Net which turns Avatar: The Last Airbender into a Western fantasy while keeping the plot mostly intact. However, the author hasn't updated for a very long time, so it's sadly a Dead Fic.
- NGE: A Century Apart asks the question, "What would happen if Neon Genesis Evangelion took place 100 years earlier than it did in canon?"
- Matrose Mond by David H. Olivier sets the action of Sailor Moon in Nazi Germany.
- The Doctor Who fanfic collection Really Stretching UNIT Dating has stories placing the Brigadier and UNIT in the 1790s, 1920s, 2020s, Ancient Greece and 12th century.
- In universe, Twilight Sparkle's Secret Shipfic Folder has "Hearthswarming: A Detailed Account".
- Batman 1939 explores Batman's fight to clean up Gotham during World War II. While Batman himself was around in 1939, the fic includes characters and concepts that were not part of the Batman mythos in The Golden Age of Comic Books.
- Horatio Hornblower takes place in the Age of Sail era, and the TV adaptation is specifically set in the French Revolutionary Wars and the Napoleonic Wars. Half Jack is an AU fic from World War I. It starts in 1915, roughly alongside the Battle of Loos and after Dogger Bank. Horatio and Archie are Sub-Lieutenants instead of midshipmen.