Surname Ястин (Jastin 
, Yastin 
, Ястин 
) , around the globe, is quite a rare last name. The cognomen Ястин is habitual in Tanzania, where it is quite a rare surname, Myanmar, where it is a rare surname, and Malaysia. In absolute terms, it is the most numerous in Tanzania, India, and Indonesia. More frequently, Ястин is the forename as well as the last name.