Olba or Olbe (Ancient Greek: Ὄλβη; Turkish: Oura) was an ancient city and bishopric in the Roman province of Isauria, in present-day southern Turkey. It is included in the Catholic Church's list of Latin titular sees.

The site of Olba, within the broader Olbian region, was identified by archaeologist Theodore Bent and his wife in March 1890, during their survey of part of Cilicia Tracheia.

Olba was a city of Cetis in Cilicia Aspera, later forming part of Isauria. It was situated at the foot of the Taurus Mountains, on a tributary of the Calycadnus.

According to Greek mythology, Olbe had been built by Ajax, half-brother of Teucer; it contained a temple of Zeus, whose priest once ruled over all Cilicia Aspera. Strabo described it:

The temple would have been closed when Christianity was introduced during the persecution of pagans in the late Roman Empire.

During the 1st century BC, it was ruled by the local tyrants Zenophanes and his daughter Aba. Later, it became a Roman colony. Strabo calls it Olbe (Ὄλβη). Ptolemy calls it Olbasa (Ὄλβασα). Stephanus of Byzantium calls it Olbia (Ὀλβία).

A coin of Diocæsarea, Olbos; Hierocles (Synecdemus, 709), Olbe; Basil of Seleucia (Mirac. S.Theclæ, 2, 8) and the Greek Notitiæ episcopatuum, Olba. The primitive name must have been Ourba or Orba, found in Theophanes the Chronographer, hence Ourbanopolis in "Acta S. Bartholomei".

In Christian times, it was regarded as belonging to Isauria, and was the seat of a bishop.