Iimoriyama Castle (飯盛山城, Iimoriyama-jō) was a Sengoku period mountain-top castle in Osaka Prefecture, Japan.

It was the original base of power for the Miyoshi clan.

[1][2] Iimoriyama Castle was built by Kizawa Nagamasa and was later controlled by the Miyoshi clan.

[1] In 1564, Miyoshi Nagayoshi died in the castle.

[6] The castle is now only ruins, with some stone walls, moats and Dobashi bridges.