Rūm (Arabic: روم [ruːm], collective; singulative: رومي Rūmī [ˈruːmiː]; plural: أروام ʼArwām [ʔarˈwaːm]; Persian: روم Rum or رومیان Rumiyān, singular رومی Rumi; Turkish: Rûm or Rûmîler, singular Rûmî), also romanized as Roum, is a derivative of the Aramaic (rhπmÈ) and Parthian (frwm) terms, ultimately derived from Greek Ῥωμαῖοι (Rhomaioi, literally 'Romans'). Both terms are endonyms of the pre-Islamic inhabitants of Anatolia, the Middle East and the Balkans and date to when those regions were parts of the Eastern Roman Empire.

The term Rūm is now used to describe:

• Remaining pre-Islamic ethnocultural Christian minorities living in the Near East and their descendants, notably the Antiochian Greek Christians who are members of the Greek Orthodox Church of Antioch and the Melkite Greek Catholic Church of Syria, Lebanon, Jordan, Israel, Palestine, and the Hatay Province in Southern Turkey whose liturgy is still based on Koine Greek.
• Orthodox Christian citizens of modern Turkey originating in the pre-Islamic peoples of the country, including Pontians from the Black Sea mountains in the north, Cappadocians from Turkey's central plateau, and Hayhurum from eastern Turkey.
• Topographical names within Anatolia (e.g. Erzurum and Rumiye-i Suğra) and the Balkans (Rumelia) stemming from the legacy of the Eastern Roman Empire in those areas, or of the Seljuk Sultanate of Rûm, a medieval Muslim state that ruled over recently conquered Byzantines (Rûm) in central Asia Minor from 1077 to 1308.