Caucasus hunter-gatherer (CHG), also called Satsurblia cluster, is an anatomically modern human genetic lineage, first identified in a 2015 study, based on the population genetics of several modern Western Eurasian (European, Caucasian and Near Eastern) populations.

It represents an ancestry maximised in some Upper Paleolithic and Mesolithic hunter-gatherer groups in the Caucasus. These groups are also very closely related to Mesolithic hunter-gatherers and Neolithic farmers and pastoralists in the Iranian Plateau (Iranian hunter-gatherer cluster), who are sometimes included within the CHG group. Ancestry that is closely related to CHG-Iranian hunter gatherers and farmers is also known from further east, including from the Bactria–Margiana Archaeological Complex and the Harappan/Indus Valley Civilisation. Caucasus hunter-gatherers and Eastern hunter-gatherers are ancestral in roughly equal proportions to the Western Steppe Herders (WSH), who were widely spread across Europe and Asia beginning during the Chalcolithic.

The CHG lineage is suggested to have diverged from the ancestor of Western Hunter-Gatherers (WHGs) probably during the Last Glacial Maximum (sometime between 45,000 and 26,000 years ago). They further separated from the Anatolian hunter-gatherer (AHG) lineage later, suggested to around 25,000 years ago during the late LGM period. The Caucasus hunter-gatherers managed to survive in isolation since the late LGM period as a distinct population, and display high genetic affinities to Mesolithic and Neolithic populations on the Iranian plateau, such as Neolithic specimens found in Ganj Dareh. The CHG display higher genetic affinities to European and Anatolian groups than Iranian hunter-gatherers do, suggesting a possible cline and geneflow into the CHG and less into Mesolithic and Neolithic Iranian groups.

According to one model, the Mesolithic/Neolithic Iranian lineage basal to the Caucasus hunter-gatherers are inferred to derive significant amounts of their ancestry from Basal Eurasian (c. 38–48%), with the remainder ancestry being closer to Ancient North Eurasians or Eastern European Hunter-Gatherer (ANE/EHG; c. 52–62%). The CHG displayed an additional ANE-like component (c. 10%) than the Neolithic Iranians do, suggesting they may have stood in continuous contact with Eastern Hunter-Gatherers to their North. The CHG also carry around 20% additional Paleolithic Caucasus/Anatolian ancestry. Lazaridis et al. (2016) models the CHG as a mixture of Neolithic Iranians, Western Hunter-Gatherers and Eastern Hunter-Gatherers. In addition, CHG cluster with early Iranian farmers, who significantly do not share alleles with early Levantine farmers.

An alternative model without the need of significant amounts of ANE ancestry has been presented by Vallini et al. (2024), suggesting that the initial Iranian hunter-gatherer-like population which is basal to the CHG formed primarily from a deep Ancient West Eurasian lineage ('WEC2', c. 72%), and from varying degrees of Ancient East Eurasian (c. 10%) and Basal Eurasian (c. 18%) components. The Ancient West Eurasian component associated with Iranian hunter-gatherers (WEC2) is inferred to have diverged from the West Eurasian Core lineage (represented by Kostenki-14; WEC), with the WEC2 component staying in the region of the Iranian Plateau, while the proper WEC component expanded into Europe.

Irving-Pease et al. (2024) models CHG as being derived from an Out of Africa population that split into basal Northern Europeans and West Asians. The latter was where CHG originated from.

At the beginning of the Neolithic, at c. 8000 BC, they were probably distributed across western Iran and the Caucasus, and people similar to northern Caucasus and Iranian plateau hunter-gatherers arrived before 6000 BC in Pakistan and north-west India. A roughly equal merger between the CHG and Eastern Hunter-Gatherers in the Pontic–Caspian steppe resulted in the formation of the Western Steppe Herders (WSHs). The WSHs formed the Yamnaya culture and subsequently expanded massively throughout Europe during the Late Neolithic and Early Bronze Age c. 3000—2000 BC.

Caucasus hunter gatherer/Iranian-like ancestry, was first reported as maximized in hunter-gatherers from the South Caucasus and early herders/farmers in northwestern Iran, particularly the Zagros, hence the label "CHG/Iranian".