During setup, the Apple Watch will ask you which wrist you intend to wear it on. Answer, an it will automatically set it up for the proper wrist. If you later change your mind, however, or lend it to someone who wants to wear it on a different wrist, it's easy to change.
Note: When wearing an Apple Watch left-handed — i.e. on your right wrist — the button positions will be reversed. That means the Digital Crown will be on the "bottom" and the side button on the "top". It won't affect the way the watch works.
How to configure the Apple Watch for left handed use
- Launch the Settings app from the main menu of your Apple Watch.
- Tap on General.
- Tap on Orientation.
- Tap on Right under Wrist.
- Tap on Left under Crown.