Kasia is a Polish diminutive of Katarzyna, the Polish form of Katherine. In Poland, Kasia functions as a common standalone given name and informal nickname, reflecting the Slavic tradition of affectionate shortenings. The suffix -sia is a typical Polish diminutive ending, suggesting closeness and endearment. Etymology The journey of Kasia begins with Katherine (Greek Αἰκατερίνη, Ai′katerine), whose exact origin is uncertain, but theories tie it to Hecate, or later association with Greek καθαρός meaning pure due to early Christian influence. In Polish, the long form Katarzyna is standard, while Kasia is its clipped counterpart. Meaning: Diminutive of Katarzyna (ultimately from Greek Aikaterine) Origin: Polish Type: Given name, diminutive (often used independently) Usage Regions: Poland