Flavius Eutolmius Tatianus (Greek: Φλαούιος Εὐτόλμιος Τατιανὸς; fl. 357–392) was a Senator of the Late Roman Empire. Born in Sidyma, Lycia, by the 360s Tatianus was governor of the Thebaid. He governed Egypt, from 370 was comes Orientis, and from 374 was comes sacrarum largitionum. In 388 he was appointed Praetorian prefect of the East, and in 392 was removed from that role and arrested; he was later exiled.