Halki or Chalki can refer to several different things:

• Chalki (also Khalki or Halki), a Greek island in the Dodecanese
• Heybeliada (Chalki in Greek), one of the Princes' Islands near Istanbul
  • The Halki seminary, located on Heybeliada
• Chalaki, Golestan, in northern Iran, sometimes spelt Chalki
• Ḫalki, Hittite grain deity.
• Ige-Halki, a king of ancient Elam (mid 14th century BCE).

Not to be confused with Chalcis, a town in Greece.