Last name Блай (Blay 
, Blai 
, Bly 
) , in the world, is a common cognomen. The cognomen Блай is characteristic of Ghana, where it is quite a common surname, Guadeloupe, and Israel, where it is quite a rare surname. Measured by absolute frequency, the name is most common in Ghana, the United States, and France. Much less frequently, Блай is the forename as well as the last name.