Last name باى (Baa 
, Bye , باى 
) , in the world, is a common cognomen. The surname باى is characteristic of Norway, where it is quite a common surname, Aruba, and Bosnia and Herzegovina, where it is quite a rare surname. Measured by absolute frequency, this name is the most popular in India, the United States, and China. Much less frequently, باى is the forename as well as the last name.