Adapazarı is a city in northwestern Turkey and the capital of Sakarya Province. The province itself was originally named Adapazarı as well. The city has a population of 953.181 (as of 2015).
Adapazarı is the location of a large automobile factory owned by Toyota Motor Corporation. Silk and linen industries, and an export of tobacco, walnut-wood, cocoons and vegetables catering to İstanbul market is also considerable.
Historically, it was situated on the old military road from Istanbul to the east, and connected by a branch line with the Anatolian railway since the end of the 19th century. A large part of the population is of Black Sea ancestry, from cities like Trabzon and Rize. Hayhurum had a significant presence in Adapazarı where there had been an Armenian community since 1608. They have been included in the 1923 agreement for Exchange of Greek and Turkish Populations between Turkey and Greece, and settled in various parts of Greece. Precious objects of culture and else belonging to this small community is being displayed today in Athens Benaki Museum.