The Upper Paleolithic (or Upper Palaeolithic) is the third and last subdivision of the Paleolithic or Old Stone Age. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories coinciding with the appearance of behavioral modernity in early modern humans, until the advent of the Neolithic Revolution and agriculture.

Anatomically modern humans (i.e. Homo sapiens) are believed to have emerged in Africa around 300,000 years ago. It has been argued by some that their ways of life changed relatively little from that of archaic humans of the Middle Paleolithic, until about 50,000 years ago, when there was a marked increase in the diversity of artefacts found associated with modern human remains. This period coincides with the most common date assigned to expansion of modern humans from Africa throughout Asia and Eurasia, which contributed to the extinction of the Neanderthals.

The Upper Paleolithic has the earliest known evidence of organized settlements, in the form of campsites, some with storage pits. Artistic work blossomed, with cave painting, petroglyphs, carvings and engravings on bone or ivory. The first evidence of human fishing is also found, from artefacts in places such as Blombos cave in South Africa. More complex social groupings emerged, supported by more varied and reliable food sources and specialized tool types. This probably contributed to increasing group identification or ethnicity.

The peopling of Australia most likely took place before c. 60 ka. Europe was peopled after c. 45 ka. Anatomically modern humans are known to have expanded northward into Siberia as far as the 58th parallel by about 45 ka (Ust'-Ishim man). The Upper Paleolithic is divided by the Last Glacial Maximum (LGM), from about 25 to 15 ka. The peopling of the Americas occurred during this time, with East and Central Asia populations reaching the Bering land bridge after about 35 ka, and expanding into the Americas by about 15 ka. In Western Eurasia, the Paleolithic eases into the so-called Epipaleolithic or Mesolithic from the end of the LGM, beginning 15 ka. The Holocene glacial retreat begins 11.7 ka (10th millennium BC), falling well into the Old World Epipaleolithic, and marking the beginning of the earliest forms of farming in the Fertile Crescent.