Rename states and regions

[Templar]

It is possible to rename states and regions?

[tonypa]

Not within the game.

There are many files you can edit in the folder:
Steam\SteamApps\common\Europa Universalis IV\localisation
Notice that you should always start new game after editing as much of the values are written in the savefile once game is started.

There are files for 4 supported languages, if you play with English, just pick a file with english int he name. For example
areas_regions_l_english.yml

If you open this file, there is a line with "xxx_area_name" for each area, like this:
brittany_area_name:0 "Brittany"
just replace it with whatever you want:
brittany_area_name:0 "Bretagne"
save the file and start new game.