Cahersiveen (Irish: Cathair Saidhbhín, meaning "Little Sadhbh's stone ringfort")—alternate spellings Cahirsiveen, Cahirciveen or Caherciveen—is a town in the Region of Skellig Kerry, County Kerry, Ireland. It is located on the River Fertha and is the principal town of the Iveragh Peninsula. Cahersiveen is near Valentia Island and is connected to the Irish road network by the N70 road.