Edirne (ancient Hadrianopolis) is a city in Thrace, the westernmost part of Turkey, close to the borders with Greece and Bulgaria. Edirne served as the capital city of the Ottoman Empire from 1365 to 1457, when Constantinople (Istanbul) became the empire's new capital. At present, Edirne is the capital of the Edirne Province in Turkish Thrace. The city's estimated population in 2002 was 128,400, up from 119,298 in 2000. It has consulates of Bulgaria, Germany (Honorary), Greece, Romania (Honorary) and Slovakia (Honorary). Its sister cities are Haskovo and Yambol in Bulgaria and Alexandroupoli in Greece.

The city was founded as Hadrianopolis, named for the Roman Emperor Hadrian. This name is still used in the Modern Greek (Αδριανούπολη). The English name Adrianople, by which the city was known until the Turkish Postal Service Law of 1930, has fallen into disuse. The Turkish Edirne, the Bulgarian Одрин (Odrin), and the Serbian Једрене (Jedrene) are adapted forms of the name Hadrianopolis.