Would SmartThings work in my country?

I live in Poland. Would SmartThings work here if I used a transformer?

There is also a somewhat longer answer…

First, you should only consider the UK version, this is designed for EU radio frequencies.

But secondly, you should check if it will work with the typical sensors and devices that you need and are typically available in EU.
If you are not sure, you will most certainly ending up asking for support, and then it might get more tricky, because UK version is only supported in mainland UK and Ireland as far as I know.