The Chalcolithic (English: /ˌkælkəˈlɪθɪk/),[1] a name derived from the Greek: χαλκός khalkós, "copper" and from λίθος líthos, "stone"[1] or Copper Age,[1] also known as the Eneolithic[1] or Aeneolithic[2] (from Latin aeneus "of copper") is an archaeological period which researchers now regard as part of the broader Neolithic. Earlier scholars defined it as a transitional period between the Neolithic and the Bronze Age. In the context of Eastern Europe, archaeologists often prefer the term "Eneolithic" to "Chalcolithic" or other alternatives.

In the Chalcolithic period, copper predominated in metalworking technology. Hence it was the period before it was discovered that by adding tin to copper one could create bronze, a metal alloy harder and stronger than either component.

The archaeological site of Belovode, on Rudnik mountain in Serbia, has the worldwide oldest securely-dated evidence of copper smelting at high temperature, from c. 5000 BC (7000 BP).[3][4] The transition from Copper Age to Bronze Age in Europe occurs between the late 5th and the late 3rd millennia BC. In the Ancient Near East the Copper Age covered about the same period, beginning in the late 5th millennium BC and lasting for about a millennium before it gave rise to the Early Bronze Age.