Across the world, Costen (Kosti 
, Costen 
) is a rare unisex first name. The first name Costen is characteristic of Finland, where it is quite a rare male name, Albania, and Georgia, where it is a rare male name. Measured by absolute frequency, this name is the most popular in Indonesia, Finland, and India. More prevalently, Costen is the last name as well as the forename.