Aginskoye (; , Aga; , Ag) is an urban locality (an urban-type settlement) and the administrative center of Agin-Buryat Okrug and of Aginsky District in Zabaykalsky Krai, Russia. It is located in the valley of the Aga River (the Amur basin). Population: 7,200 (1967).
It was founded in 1781 or, according to other sources, in 1811.
Within the framework of administrative divisions, Aginskoye serves as the administrative center of Aginsky District and is subordinated to it. As a municipal division, the urban-type settlement of Aginskoye together with one rural locality in Aginsky District is incorporated as Aginskoye Urban Okrug.
Aginskoye experiences a dry-winter borderline humid continental climate/subarctic climate (Köppen climate classification: Dwb/Dwc) with very cold, very dry winters and warm, wet summers.