Polish form of Casper, traditionally linked to a Persian name meaning "treasurer" or "keeper of the treasure."
Kacper is the Polish form of Caspar (also spelled Casper or Jasper in other European traditions), a name whose origins reach back through medieval Latin into Persian. The Persian name Gathaspar or Gaspar — meaning "treasurer" or "keeper of the treasure" — was assigned by early Christian tradition to one of the biblical Magi, the three wise men who brought gifts to the infant Jesus. Though the Magi are unnamed in the Gospel of Matthew, later tradition supplied them with the names Caspar, Melchior, and Balthasar, and the name Caspar became embedded in Christian European culture from at least the sixth century onward.
In Poland, Kacper has been in continuous use for centuries and remains one of the country's most popular given names. It carries the warmth of both religious tradition and folk familiarity — Kacper is not a formal or distant name in Polish culture but rather an approachable, everyday one, common in villages and cities alike. The feast day of the Three Magi on January 6th (Epiphany, or Trzech Króli in Polish) gives Kacper its name day celebration, one of the most widely observed in the Polish calendar.
Outside Poland, the name appears across central and Eastern Europe in related forms — Kasper in Scandinavian countries, Caspar in Germany and the Netherlands, Jasper in English-speaking countries (via a different phonetic evolution). The English-speaking world knows Casper perhaps most immediately through the friendly cartoon ghost, a twentieth-century American character who softened the name's medieval gravity. Kacper, however, retains its full cultural weight: a name of gift-bearers and treasurers.