Overview
Since we’ve yet to get a fix/update to allow us to rename cities, I’ve found a somewhat simple (but quite annoying) workaround to do so for the time being.
Guide
1. In order to rename a city, navigate to your Civilization VI installation folder (usually found under C:Program FilesSteamsteamappscommonSid Meier’s Civilization VI).
2. From there, open Base, then Assets, then Text and finally your install language.
You should now be somewhere like this: C:Program FilesSteamsteamappscommonSid Meier’s Civilization VIBaseAssetsTexten_US .
3. Finally, open the file named CityNames_Text.xml with the text editor of your choice, and find the civilization/city you wish to rename. Simply change the city name there, save, and reload the game, and your city(ies) should be renamed!
Of course, this will persist over games, and is only visible to you unless other players make the same changes, but it’s better than nothing while we wait for a patch/update that adds back this much needed feature!