When you do a backup of your Apple Watch, that backup is stored locally on your iPhone. If you backup your iPhone to iCloud or iTunes, your Apple Watch backup will also be backed up on your computer or in the cloud.
Unless you sync music and photos to your Apple Watch, those backups usually don’t amount for much space. Typically, an Apple Watch backup takes a few hundred kilobytes on a device. It is negligible, but for the neat freaks like me, that might still be too much.
This post will show you where to find your old Apple Watch backups and how to delete them.
I recently restored my Apple Watch several times in a row, which led to several backups being made. These backups contain roughly the same data, so they are redundant and unnecessary. I could very well leave them intact, but why keep stuff that you don’t need, and can also bring confusion?

How to remove Apple Watch backups

1) Launch the Settings app on your iPhone.

2) Navigate to General > iPhone Storage. Wait a few seconds for data to load.
3) Scroll down and locate the Watch section. Tap on it. Your previous Apple Watch backups will appear under the Documents & Data section.
4) Swipe from right to left on a backup to delete it. Alternatively, tap on Remove All Backups to delete all backups in one fell swoop.
As we said before, there is no big benefit to removing your old Apple Watch backups as they are fairly small in size. In my case, seen on the screenshot above, it just helped cleanup duplicate backups that weren’t really necessary. Your mileage may vary.