The 9th millennium BC spanned the years 9000 BC to 8001 BC. In chronological terms, it is the first full millennium of the current Holocene epoch that is generally reckoned to have begun by 9700 BC. It is impossible to precisely date events that happened around the time of this millennium and all dates mentioned here are estimates mostly based on geological and anthropological analysis, or by radiometric dating.

The Holocene is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene is an interglacial period within the ongoing glacial cycles of the Quaternary, and is equivalent to Marine Isotope Stage 1.