is my US xbox compatible with UK electrical voltage?

You just need to UK cable, any transformer that would be able to handle an Xbox would probably cost more than the Xbox

It's multi-voltage, just needs a UK power cable. The cable is called a Figure 8 and it can be bought in many UK electrical stores or online.

(I'm from the UK).

Hi

It is always best to buy the console in the in the country where you intend to use it but most European country's use the same voltage as the United Kingdom so it should be okay to just change the power lead to a UK one. Please see the guide below to confirm
it the UK voltage matches where the console is being purchased from.

http://www.worldstandards.eu/electricity/plug-voltage-by-country/

Normal electricity? lol. Most of the world uses 220.

All you need is a UK to US adapter if the S is multi-voltage. Usually, electronics are now-a-days.

Hi

Yes it will work. The internal power supply is multivoltage. You just need a fig 8 power cable. You can get these from anywhere.