Last name Руя (Ruja 
, Ruya 
, Ruia 
) , throughout the world, is quite a common surname. The last name Руя is characteristic of Romania, where it is quite a rare surname, Latvia, and Moldova. Not in comparison with a country's population, this name is the most popular in India, Romania, and Indonesia. Likewise, Руя is the forename as well as the last name.