Vaison-la-Romaine is a commune . It is found in the region Provence-Alpes-C Ã te d'Azur in the Vaucluse department in the south of France .
Vaison-la-Romaine ( Latin : Vasio Vocontiorum ) is a commune in the Vaucluse department in the Provence-Alpes-C Ã te d'Azur region in southeastern France .