Dolinsk (Russian: Долинск) is a town and the administrative center of Dolinsky District of Sakhalin Oblast, Russia, located in the southeast of the Sakhalin Island in the valley of the Naiba River and its tributaries, about 45 kilometers (28 mi) north of Yuzhno-Sakhalinsk and 10 kilometers (6.2 mi) from the coast of the Terpeniye Bay of the Sea of Okhotsk. Population: 12,200 (2010 Census preliminary results); 12,555 (2002 Census); 15,653 (1989 Census).