The Vilayet of Van (ولايت وان, Vilâyet-i Van; Armenian: Վանի վիլայեթ, Vani vilayet') was one of the Six vilayets of the Ottoman Empire. At the beginning of the 20th century it reportedly had a population of about 400,000 and an area of 15,000 square miles (39,000 km²).

The province had been established in the 16th after the Peace of Amasya between Ottoman Empire and Persia. Until 19th century the borders of the province had been changed. In 1897-1902 the boundaries of vilayet didn't change. The center of province was Van. It was also the border province of the north-eastern frontier, towards Russian and Persian territory. It was consisted from sanjaks of Van and Hakkari and covered present provinces of Van, Hakkari and parts of Şırnak, Muş and Bingöl ones.

At the beginning of the 20th century it reportedly had an area of 15,440 square miles (40,000 km²), while the preliminary results of the first Ottoman census of 1885 (published in 1908) gave the population as 376,297. It should be noted that the accuracy of the population figures ranges from "approximate" to "merely conjectural" depending on the region from which they were gathered.