Eskişehir (pronounced [esˈciʃehiɾ]; Turkish: eski "old", şehir "city") (Latin: Dorylaeum; Ancient Greek: Δορύλαιον, Dorýlaion) is a city in northwestern Turkey and the capital of the Eskişehir Province. According to the 2009 census, the population of the city is 631,905. The city is located on the banks of the Porsuk River, 792 m above sea level, where it overlooks the fertile Phrygian Valley. In the nearby hills one can find hot springs. The city is 233 km (145 mi) to the west of Ankara, 330 km (205 mi) to the southeast of Istanbul and 78 km (48 mi) to the northeast of Kütahya. Known as a university town, both Eskişehir Osmangazi University and Anadolu University (which has one of the largest student enrollments in the world) are based in Eskişehir. The province covers an area of 2,678 km² (1,034 sq mi).

The name Eskişehir literally means Old City in Turkish; indeed, the city was founded by the Phrygians in about 1000 BOT. Many Phrygian artifacts and sculptures can still be found in the city's archeological museum. There is also a museum of meerschaum stone, whose production remains still notable, used to make high quality meerschaum pipes. In the fourth century AD the city moved about ten km northeast, from Karacahisar to Şehirhöyük.