Õisu

Õisu () is a small borough in Mulgi Parish, Viljandi County, in southern Estonia.

==Õisu manor== A manorial estate was established in Õisu in the 16th century, and during the Swedish time it appears to at some point have belonged to one Jesper Kruse. In 1744, during the Imperial Russian time the estate was donated by the Empress Elizabeth to the widow of Admiral Peter von Sievers. It stayed in the von Sievers family until the Estonian Declaration of Independence and the ensuing land reform when the estate was nationalised and turned into an agricultural school.