Hypaepa or Hypaipa (Ancient Greek: Ὕπαιπα, romanized: Húpaipa) was an Ancient city and (arch)bishopric in ancient Lydia, near the north bank of the Cayster River, and 42 miles from Ephesus, Ephesus and remains a Latin Catholic titular see.

Its name was derived from its situation at the foot of Mount Aipos,^{[further explanation needed]} itself a southern foothill of Mount Tmolus,

Its location was identified by the Frenchmen Cousinéry and Texier and confirmed by the excavations carried out by Demostene Baltazzi on behalf of the Ottoman government in 1892. The ruins are close to the present-day village of Günlüce (earlier known as Datbey or Tapaı; in the Ottoman vilayet of Smyrna), 4 kilometres northwest of the town of Ödemiş.

Its position looking towards the plain of Caystrus, was a strategic one on the route between Sardis and Ephesus.

In 88 BC, Hypaepa rebelled against Mithridates VI of Pontus (r. 120-63 BC) and was severely punished.

Under Roman Emperor Tiberius (AD 14-37) it was selection as a candidate for the location of a temple dedicated to worship of the Emperor, but was rejected as being too insignificant.

The Roman poet Ovid contrasted the great city of Sardis with what he called "little Hypaepa": Sardibus hinc, illinc parvis finitur Hypaepis.

Coinage of Hypaepa of the 3rd century AD are extant, until the time of Emperor Gallienus.