Askio (Greek: Άσκιο) is a mountain range in the northwestern part of the Kozani and the eastern part of the Kastoria regional units in northern Greece. The elevation of its highest peak, Siniatsiko, is 2,111 m (6,926 ft). There are forests in the northern part. It stretches from the village Kleisoura in the northwest to Xirolimni in the southeast, over a length of about 30 km (19 mi). The nearest mountains are the Verno to the northwest, the Vourinos to the south and the Vermio to the northeast.