Around the globe, Casian (Casian 
, Цасян 
) is quite a rare male given name. The forename Casian is characteristic of Aland Islands, where it is quite a common masculine name, Moldova, where it is quite a rare boy's name, and Romania. Not in comparison with a country's population, it is commonest in Tanzania, Romania, and Moldova. Likewise, Casian is the last name as well as the forename.