Ayask (Persian: آيسك) is a city in, and the capital of, Ayask District of Sarayan County, South Khorasan province, Iran.

At the 2006 census, its population was 5,023 in 1,399 households. The following census in 2011 counted 4,756 people in 1,488 households. The latest census in 2016 showed a population of 5,143 people in 1,639 households.