In the 8th century BC the settlement of Cotyora was founded in this area as one of a string of colonies along the Black Sea coast established by the Miletians. The area came under the control of the Danishmends, then the Seljuk Turks in 1214 and 1228 and Haci Emir Ogulları Beyligi in 1346. Afterwards it passed to the dominion of the Ottomans in 1461 with the Empire of Trabzon.
The modern city was founded by the Ottomans as Bayramlı near Eskipazar as a military outpost 5 km west of Ordu.
In 1869, the name was changed to Ordu and united with the districts of Bolaman, Perşembe, Ulubey, Hansamana (Gölköy) and Aybastı. Ordu province was created at 17 April 1920.