Surname Кассиан (Cassian 
, Cassianus 
, Кассиан 
) , all over the world, is quite a rare family name. The cognomen Кассиан is characteristic of Tanzania, where it is quite a rare surname, Cameroon, where it is a rare surname, and Romania. In absolute terms, the name is most common in Tanzania, Cameroon, and Mexico. Also, Кассиан is the forename as well as the last name.