John Casimir

John Casimir may refer to:

  • John II Casimir of Poland (1609–1672)
  • Johann Casimir of Simmern (1543–1592)
  • John Casimir, Duke of Saxe-Coburg (1564–1633)
  • John Casimir (clarinetist) (1898–1963)
  • John Casimir, Count Palatine of Kleeburg (1589–1652), father of Karl X Gustav of Sweden
  • John Casimir Ehrnrooth, Finnish soldier
  • John Casimir Zichy Woinarski, Australian ornithologist