Ōuchi-shi Yakata (大内氏館, Ōuchi-shi Yakata) was the fortified residence of the Ōuchi clan in Yamaguchi, Japan.

Ōuchi-shi Yakata has been designated as a National Historic Sites along with Ryōun-ji temple.

[2] Its ruins have been protected as a nationally designated historic site.

In 1556, Ōuchi Yoshinaga built Kōnomine Castle as a supporting castle of Ōuchi-shi Yakata because Ōuchi-shi Yakata was considered unsuitable for withstanding a siege.

[4][5] but Mōri Motonari`s army advanced to Suō Province, Ōuchi Yoshinaga left Ōuchi-shi Yakata and Kōnomine Castle without resistance.