667 BC

667 BC was a year in the pre-Julian Roman calendar. As the Roman calendar was not fully standardized at this point, and other calendars were also in use across the ancient world, correlating this year with other chronological systems requires some approximation.

Historical events believed to have occurred around this year include:

• Byzantium (later Constantinople, now Istanbul) is traditionally considered to have been founded by Greek colonists from Megara, led by Byzas. The precise date is based on later reconstructions and may not be entirely accurate, but tradition generally places the founding near this year.
• Assurbanipal of Assyria continues his military campaigns, expanding the Neo-Assyrian Empire. The specifics of his activities in this particular year are not always well-documented, but it falls within his reign and period of active campaigning.