Jan Kazimierz Sapieha the Younger (Lithuanian: Jonas Kazimieras Sapiega jaunesnysis) (1637–1720) was a Grand Hetman of Lithuania since 1682. He held the title of a Duke since 1700. In 1681 he became Field Hetman of Lithuania, the following year he also became the voivode of Vilnius.

He is the founder of Sapieha Palace in Vilnius, designed by Pietro Perti from Italy.