John of Denmark may refer to:
- John, King of Denmark (1455–1513)
- John of Denmark (1518–1532)
- John II, Duke of Schleswig-Holstein-Haderslev (1521–1580)
- John II, Duke of Schleswig-Holstein-Sonderburg (1545–1622)
- John, Prince of Schleswig-Holstein (1583–1602)
- Prince Johann of Schleswig-Holstein-Sonderburg-Glücksburg (1825–1911)