Osaka Prefecture Ōsakasayama has a Humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

From 1600 to the Meiji restoration it was the seat of the Later Hōjō clan, rulers of Sayama Domain under the Tokugawa shogunate.

Ōsakasayama has a mayor-council form of government with a directly elected mayor and a unicameral city council of 15 members.

Ōsakasayama, collectively with Tondabayashi and the smaller municipalities of Minamikawachi District contributes two members to the Osaka Prefectural Assembly.

In terms of national politics, the city is part of Osaka 15th district of the lower house of the Diet of Japan.