The Sinyaya (, , ) is a river in Verkhnyadzvinsk Raion of Vitebsk Region of Belarus, in Zilupe, Ludza, and Cibla municipalities of Latvia, and in Sebezhsky, Krasnogorodsky, and Ostrovsky Districts of Pskov Oblast in Russia, part of the Baltic Sea basin. It is a left tributary of the Velikaya River. It is long, and the area of its basin .