The Osaka Prefectural Assembly is the legislature of Osaka Prefecture. As in all prefectures, it is elected to four-year terms by single non-transferable vote in multi- and single-member districts and is responsible for enacting and amending prefectural by-laws, approving the budget and important administrative appointments in the prefectural government, including the prefecture's vice governors. The assembly has a regular membership 88 members.

The Osaka Restoration Association , also referred to as One Osaka, is a regional political party in Osaka Prefecture, Japan. Founded in 2010 by then-Governor Tōru Hashimoto, its main platform is pursuing the Osaka Metropolis plan of merging the prefecture and some of its cities into "One Osaka", reducing overlapping bureaucratic organizations of the prefecture and the city of Osaka, towards Dōshūsei.