Cahersiveen—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. It has a population of 1,294 (CSO 2006).
The Catholic church in the town is the only one in Ireland named after a lay person, Daniel O'Connell. It is situated on the slopes of Beentee. It also contains a decommissioned Royal Irish Constabulary barracks, now a heritage centre, which according to legend, was built from the plans for a British barracks in India that got mixed up (a very common myth that occurs in many Irish garrison towns).
Cahersiveen was where the first shots of the Fenian Rising were fired in 1867.