Castellet-en-Luberon, known simply as Castellet until 2018, is a commune in the Vaucluse department in the Provence-Alpes-Côte d'Azur regio…Castellet-en-Luberon, known simply as Castellet until 2018, is a commune in the Vaucluse department in the Provence-Alpes-Côte d'Azur region in Southeastern France. In 2021, it had a population of 113.