Moreover, can you use your Apple Watch in Europe?
Yes - Apple Watch Series 3 (GPS) can be used in any country.
Secondly, can I use my Apple Watch cellular overseas? Yes. The cellular features of the watch will not work, but it will work in conjunction with your phone normally.
Moreover, does Apple Watch work internationally?
About international roaming
Unlike iPhone, there isn't a worldwide Apple Watch model that supports all cellular bands used globally. When your Apple Watch is connected to your iPhone or a previously joined Wi-Fi network, you can still use all the features of your Apple Watch, even if cellular isn't available.
Are Apple watches region locked?
The Apple Watches are not locked to a specific carrier, but they are regional devices. And this is only for the cellular versions. If this is a GPS only device, then it doesn't matter.