Surname Rousia (Руся 
, Rousia 
, Русиа ) , globally, is a rare cognomen. The last name Rousia is habitual in Greece, where it is a rare surname, Algeria, where it is a very rare surname, and Kazakhstan. Measured by absolute frequency, this name is the most popular in Algeria, Greece, and Russia. Also, Rousia is the forename as well as the last name.