Colli a Volturno is a comune in the Province of Isernia in the Italian region Molise, located about 45 kilometres west of Campobasso and about 11 kilometres west of Isernia. Colli a Volturno borders the following municipalities: Cerro al Volturno, Filignano, Fornelli, Macchia d'Isernia, Montaquila, Monteroduni, Rocchetta a Volturno, Scapoli.