The library of Celsus is an ancient Roman building in Ephesus, Anatolia, now part of Selçuk, Turkey. It was built in honour of the Roman Senator Tiberius Julius Celsus Polemaeanus (completed in 135 AD) by Celsus' son, Gaius Julius Aquila (consul, 110 AD). The library was built to store 12,000 scrolls and to serve as a mausoleum for Celsus, who is buried in a crypt beneath the library.
The interior of the library was destroyed, supposedly by an earthquake in 262 A.D., and the façade by another earthquake in the tenth or eleventh century A.D. It lay in ruins for centuries, until the façade was re-erected (anastylosis) by archaeologists between 1970 and 1978.