Family name Кассий (Cassius 
, Casio 
, Кассий 
) , around the world, is a common surname. The family name Кассий is habitual in Saint Lucia, where it is quite a common surname, Philippines, where it is quite a rare surname, and Peru. In absolute terms, it is commonest in Philippines, Mexico, and Peru. Also, Кассий is the forename as well as the last name.