The area of the modern town of Yosano was within ancient Tango Province, and the place name of "Yosa" dates from records of the early 8th century.

The town of Kaya and villages of Yosano and Iwataki were established within Yosa District with the creation of the modern municipalities system on April 1, 1889.

Yosano has a mayor-council form of government with a directly elected mayor and a unicameral town council of 16 members.

In terms of national politics, the town is part of Kyoto 5th district of the lower house of the Diet of Japan.

A type of crêpe fabric called Tango chirimen has bene a famous local product since the Edo period.