O. orientalis
# O. orientalis

O. orientalis may refer to:

* Octoknema orientalis, a plant species endemic to Tanzania
* Onchidella orientalis, an air-breathing sea slug species
* Orosius orientalis, the common brown leafhopper, a leafhopper species found in Australia
* Ovis orientalis (or O. aries orientalis), the mouflon, a wild sheep species
* Oxychilus orientalis, an air-breathing land snail species found in Slovakia
