The Ōmi Provincial Capital ruins (近江国庁跡, Ōmi Kokuchō ato) is an archaeological site with the ruins of a Nara to Heian period government administrative complex located in what is now the Ōe neighborhood of the city of Ōtsu, Shiga prefecture in the Kansai region of Japan.

[1] In the late Nara period, after the establishment of a centralized government under the Ritsuryō system, local rule over the provinces was standardized under a kokufu (provincial capital), and each province was divided into smaller administrative districts, known as (郡, gun, kōri), composed of 2–20 townships in 715 AD.

[2] The kokufu complex contained the official residence and offices of the kokushi, the official sent from the central government as provincial governor, along with buildings housing offices concerned with general administration, farming, finance, police and military.

The Sōyama Site (惣山遺跡) has the foundations for twelve granaries that were used for storing of taxation rice.

It is a smaller moated and palisaded enclosure, and contains the remains of buildings from three construction phases in a planned arrangement.

The purpose of these buildings are unknown, but as the roof tiles are identical to the roof tiles used in both the Soyama Site and the Ōmi Provincial Capital site, it is believed to contain some of the offices which made up the provincial government administration.