The Vysun, Vulsun or Isun (Ukrainian: Висунь) is a river of Ukraine, flowing through the Mykolaiv region. It is a right tributary of the Inhulets River. It has a length of 195 km and begins in the Dnieper Upland and flows south through Prychornomorskoy Lowland, through the district center of Kazanka. During season it is powered mainly by snowmelt.