Family name Jaj (Jaj 
, جاج 
) , globally, is quite a rare cognomen. The cognomen Jaj is characteristic of Puerto Rico, where it is quite a rare surname, Oman, where it is a rare surname, and Saudi Arabia. Measured by absolute frequency, it is commonest in Southern Asia, particularly India, Pakistan, and Bangladesh. More prevalently, Jaj is the forename as well as the last name.