The Princes' Islands are a chain of nine islands off the coast of Istanbul, Turkey, in the Sea of Marmara. The largest island is Büyükada.

During the Byzantine period, princes and other royalty were exiled on the islands, lending them their present name. During the 19th century the islands became a popular resort for Istanbul's wealthy, and Victorian-era cottages and houses are still preserved on the largest of the Prince's islands.

Today, the islands are popular tourist destinations for day trips via ferry from Istanbul. Motorized vehicles are forbidden on most of the islands, so visitors explore the islands by foot, bicycle, in horse-drawn carriages, or by riding donkeys.

A convent on Prinkipo was the place of exile for Byzantine empresses Irene, Euphrosyne, Zoe and Anna Dalassena . Leon Trotsky also spent time on Prinkipo.