The Middle Pleistocene, also known by its ICS official name of Chibanian, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.7741 Ma (774,100 years ago) and 0.129 Ma (129,000 years ago), also expressed as 774.1–129 ka. It includes the transition in palaeoanthropology from the Lower to the Middle Paleolithic over 300 ka.

The Chibanian is preceded by the Calabrian and succeeded by the Late Pleistocene. The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal. Its end roughly coincides with the termination of the Penultimate Glacial Period and the onset of the Last Interglacial period (corresponding to the beginning of Marine Isotope Stage 5).

The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the International Union of Geological Sciences (IUGS). While the three lowest ages of the Pleistocene, the Gelasian, Calabrian and Chibanian have been officially defined, the Late Pleistocene has yet to be formally defined.

The International Union of Geological Sciences (IUGS) had previously proposed replacement of the Middle Pleistocene by an Ionian Age based on strata found in Italy. In November 2017, however, the Chibanian (based on strata at a site in Chiba Prefecture, Japan) replaced the Ionian as the Subcommission on Quaternary Stratigraphy's preferred GSSP proposal for the age that should replace the Middle Pleistocene sub-epoch. The "Chibanian" name was ratified by the IUGS in January 2020.

By early Middle Pleistocene, the Mid-Pleistocene Transition had changed the glacial cycles from an average 41,000 year periodicity present during most of the Early Pleistocene to a 100,000 year periodicity, with the glacial cycles becoming asymmetric, having long glacial periods punctuated by short warm interglacial periods. Millennial-scale climatic variability continued to be highly sensitive to precession and obliquity cycles.

In central Italy, the climate became noticeably more arid from 600 ka to 400 ka.

The late Middle Pleistocene was a time of regional aridification in the Levant, with a shallow lake covering what is now the Shishan Marsh drying and developing into a marsh.

Eastern Africa's hydroclimate was governed primarily by orbital precession, although modulated significantly by the 100 kyr eccentricity cycle.