Edessa (/ɪˈdɛsə/; from Ancient Greek: Ἔδεσσα; Syriac: ܐܘܪܗܝ Urhāy, Armenian: Եդեսիա Yedesia or Armenian: Ուռհա Uṙha) was an ancient city in upper Mesopotamia, refounded on an earlier site by Seleucus I Nicator, and is now Şanlıurfa, Turkey.
The earliest name of the city was Adma (Aramaic: אדמא also written Adme, Admi, Admum) which first appeared in Assyrian cuneiform sources in the 7th century BC. A Hellenistic settlement was founded on the location of the Syrian town by Seleucus I Nicator in 304 B.C. The new settlement was named "Edessa" after the ancient capital of Macedonia, perhaps due to its abundant water, just like its Macedonian eponym. The native Syriac name of the city, "Orhay" (Syriac: ܐܘܪܗܝ), appears to correspond with the toponym Antiochia Kallirhoe "Antioch by the Kallirhoe" (Ἀντιόχεια ἡ ἐπὶ Καλλιρρόης), which is found on Edessan coins struck by Antiochus IV Epiphanes (175–164 BC). The same name appears also in Armenian as Ուռհա, transliterated Urha or Ourha, in Arabic it is الرُّهَا transliterated as Er Ruha or Ar-Ruha, commonly Urfa, and Riha in Kurdish, to the Frankish Crusaders Rohais, and in Turkish Urfa, Ourfa, Sanli Urfa, or Şanlıurfa ("Glorious Urfa"), its present name. During Byzantine rule it was named Justinopolis.