Osaka is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of 2.7 million in the 2020 census, it is also the largest component of the Keihanshin Metropolitan Area, which is the second-largest metropolitan area in Japan and the 10th largest urban area in the world with more than 19 million inhabitants.

Osaka was traditionally considered Japan's economic hub. By the Kofun period (300–538) it had developed into an important regional port, and in the 7th and 8th centuries, it served briefly as the imperial capital. Osaka continued to flourish during the Edo period (1603–1867) and became known as a center of Japanese culture. Following the Meiji Restoration, Osaka greatly expanded in size and underwent rapid industrialization. In 1889, Osaka was officially established as a municipality.