Pure
Kasia is the traditional Polish diminutive of Katarzyna, the Polish form of Katherine. It shares the same etymological roots as Katherine, which is widely believed to be derived from the Greek word 'katharos'.
Less common today
Kasia isn't in the latest US Top 1000. It last peaked at #2,292 in 2002.
Polish-Italian actress and model
Polish fashion model
Polish pop rock singer and songwriter
Lead singer of the Polish rock band Hey
US births per 5-year period, 1990βpresent (SSA data).