The House of Żeleński is a Polish princely family and one of the most influential noble families in pre-World War II Poland. The Żeleński family's coat of arms is the Ciołek coat of arms, which is one of the oldest in medieval Poland. The Żeleński family reached notable power under the late Piast dynasty, under the Polish–Lithuanian Commonwealth, during the Partitions of Poland, and in the 20th and 21st centuries.