Yao is a city located in Osaka Prefecture, Japan. As of 31 January 2022, the city had an estimated population of 263,436 in 126509 households and a population density of 6300 persons per km2. The total area of the city is 41.72 square kilometres (16.11 sq mi). The city is the birthplace of the Kawachi ondo style of folk singing.

Osaka Prefecture is a prefecture of Japan located in the Kansai region of Honshu. Osaka Prefecture has a population of 8,778,035 and has a geographic area of 1,905 square kilometres (736 sq mi). Osaka Prefecture borders Hyōgo Prefecture to the northwest, Kyoto Prefecture to the north, Nara Prefecture to the southeast, and Wakayama Prefecture to the south.