If I buy an Apple Watch Series 3 GPS in America would it work in the UK

Hi

Apple Watch Series 3 (GPS) can be used in any country in conjunction with an iPhone 5s or newer model of iPhone (running the latest version of iOS 11.x) and a carrier service plan for the iPhone from any carrier.

If buying the Apple Watch in the US, then it will be supplied with a USB Power Adapter that is localised to the US. This cannot be used in the UK without a travel adapter.

A UK model of USB Power Adapter can instead be purchased as a separate accessory in the UK:

• Apple 5W USB Power Adapter - Apple (UK)
• Apple 5W USB Power Adapter (Folding Pins) - Apple (UK)

The Limited Warranty terms for an Apple Watch purchased in the US are detailed here:

Apple One (1) Year Limited Warranty

You would need to check with Apple or an Apple Authorised Service Provider to establish whether service under warranty would be available to you in the UK.

If it's the non-cellular one then yes.

You're welcome! 🙂