The Eyalet of Silistra or Silistria (Ottoman Turkish: ایالت سیلیستره, romanized: Eyālet-i Silistre), later known as Özü Eyalet (Ottoman Turkish: ایالت اوزی, romanized: Eyālet-i Özi, lit. 'Province of Ochakiv') was an eyalet of the Ottoman Empire along the Black Sea littoral and south bank of the Danube River in southeastern Europe. The fortress of Akkerman was under the eyalet's jurisdiction. Its reported area in the 19th century was 71,140 square kilometres (27,469 sq mi).
The Vilayet of the Danube or Danubian Vilayet (Ottoman Turkish: ولايت طونه, romanized: Vilâyet-i Tuna; Bulgarian: Дунавска област, Dunavska(ta) oblast, more commonly Дунавски вилает, Danube Vilayet) was a first-level administrative division (vilayet) of the Ottoman Empire from 1864 to 1878. In the late 19th century it reportedly had an area of 34,120 square miles (88,400 km).
The vilayet was created from the northern parts of Silistra Province along the Danube River and eyalets of Niš, Vidin and Silistra. This vilayet was meant to become a model province, showcasing all the progress achieved by the Porte through the modernising Tanzimat reforms. Other vilayets modelled on the vilayet of the Danube were ultimately established throughout the empire by 1876, with the exception of the Arabian Peninsula and the by then semi-independent Egypt. Rusçuk, today Ruse in Bulgaria, was chosen as the capital of the vilayet due to its position as a key Ottoman port on the Danube.