Žitný ostrov or Rye Islan, also called Veľký Žitný ostrov (Great Rye Island) (German: Große Schüttinsel, Hungarian: Csallóköz) to differentiate it from Malý Žitný ostrov, is a river island in southwestern Slovakia, extending from Bratislava to Komárno. It lies between the Danube and its tributary Little Danube and is a major part of the Danubian Flat. It is the biggest river island in Europe with an area of 1,886 km², being 84 km long and 15 - 30 km wide.