Cognomen Вяк (Wiak 
, Вяк 
) , throughout the world, is a rare surname. The surname Вяк is characteristic of Eastern Europe, particularly Poland, where it is quite a rare surname, Slovakia, where it is a rare surname, and Czechia. In absolute terms, this name is the most popular in Poland, the United States, and Slovakia. More prevalently, Вяк is the forename as well as the last name.