Cognomen ואט (Watt 
, ואט 
) , in the world, is a common surname. The last name ואט is habitual in Jamaica, where it is quite a common surname, Australia, and New Zealand (explore the name in all countries). Not in comparison with a country's population, it is the most numerous in the United States, the United Kingdom, and Australia. Much less frequently, ואט is the forename as well as the last name.