Osroene (Ancient Greek: Ὀσροηνή), also spelled Osrohene and Osrhoene, was a Roman province which existed for nearly 400 years.

It was formed after the absorption of the Kingdom of Osroene in 214 CE [1] and served as a frontier province against the Sassanid Empire until the Muslim conquests of the 7th century.

For the whole of its existence, the province would remain a bone of contention between the Romans and their eastern neighbors, the Sassanid Persians, suffering heavily in the recurrent Roman–Persian Wars.

Being a province on the frontier it had a Roman legion stationed there, Legio III Parthica and its Castrum (homebase) was Resaena though there are some doubts on that fact.

Since Emperor Diocletian's Tetrarchy reforms during his reign 284–305 CE, it was part of the diocese of Oriens, in the praetorian prefecture of the same name.