Sayō is a town in Sayō District, Hyōgo Prefecture, Japan. It lies in the western part of the prefecture, in the Chūgoku region of Honshu. Despite often being described as a city, it is administratively a town and the seat of its district.
As of 31 March 2022, Sayō had an estimated population of 15,701 living in 6,797 households, giving it a population density of about 51 persons per square kilometre. The town covers a total area of 307.44 square kilometres (118.70 square miles), a relatively large area for a Japanese municipality of its population size.
Sayō is known for its rural landscape and low population density, with much of its area consisting of mountains and forest. The town's economy has traditionally been based on agriculture and forestry. It is also home to several historic sites and is a gateway to the surrounding natural areas of western Hyōgo Prefecture.