The region of Yao has a rich ancient history, evidenced by numerous kofun (ancient burial mounds) and archaeological sites that indicate human settlement since the Kofun period.

Geographically, Yao is situated in the central-eastern part of Osaka Prefecture, bordering Nara Prefecture to the east and characterized by a landscape that gradually slopes from the Ikoma Mountains in the east down to the Osaka Plain.

As of recent data, Yao City maintains a population of over 260,000 residents, reflecting a steady urbanization trend characteristic of suburban areas within the greater Osaka metropolitan region.

Historically, Yao thrived on traditional industries such as cotton weaving and the production of brushes, but has since diversified into manufacturing, particularly in the production of small and medium-sized machinery and metal products.

Yao is renowned for its vibrant "Kawachi Ondo" festival, a traditional folk dance and music event that originated in the Kawachi region and attracts thousands of participants and spectators annually.

One significant landmark is the Yao Castle Ruins, though little remains today, its historical significance dates back to the Muromachi period as a strategic stronghold overlooking the area.

During the Kofun period, Yao was a significant regional center, with the extensive Tamatsukuri Kofun cluster highlighting its importance as a burial ground for powerful local clans.

The city plays a vital role in the regional economy through its many small and medium-sized enterprises (SMEs) specializing in precision manufacturing, contributing significantly to Japan's industrial backbone.

The local tradition of producing "Yao brushes" (Yao-fude), particularly for calligraphy and painting, continues to be a cherished craft, though production volumes have decreased from historical peaks.

Yao serves as an important transportation hub, with the JR Yamatoji Line and Kintetsu Osaka Line providing crucial rail links connecting Osaka City with Nara Prefecture, along with a regional airport (Yao Airport) for general aviation.

After experiencing rapid population growth during Japan's post-war economic boom as a bedroom community for Osaka, Yao's population has stabilized, with recent trends showing a slight decline due to an aging society and lower birth rates.

While not a primary national political or scientific hub, Yao's industrial capacity and strategic location have historically made it a vital component of the Kansai region's economic and logistical framework.

Although Yao City itself does not host a UNESCO World Heritage Site, it is geographically close to the Mozu-Furuichi Kofun Group, a UNESCO site, underscoring the ancient imperial connections of the wider Osaka region.

Yao is also home to several historic temples and shrines, such as the Onji Kannon-ji Temple, which offers insights into the area's spiritual heritage and attracts visitors with its scenic beauty.

Yao officially became a city in 1948, following a series of mergers of towns and villages, marking its formal establishment as a significant municipality within Osaka Prefecture.