T1nk-R’s Unified Rename Blender Add-On

You can use this add-on to rename collections and objects in one go, using either plain text or regular expression terms. While Blender has built-in support to do this for objects, renaming collections had been a nightmare to me until creating this add-on. It comes with verbose mode for debugging, test mode for trying before changing, and support for undo, of course.

The add-on comes with complete documentation and a video tutorial:

You can always find the latest version in the Github repo. If you live in a developing country or if you are in a personal situation that you cannot afford for the add-on, head there and get it. If you would like to support the development of this and other add-ons, consider paying a tip.