Val-de-Chalvagne (French pronunciation: [val də ʃalvaɲ], literally Vale of Chalvagne; Occitan: Vau de Chalvanha) is a commune in the Alpes-de-Haute-Provence department in southeastern France. It was established in 1974 by the merger of the former communes Castellet-Saint-Cassien, Montblanc and Villevieille.

The population data given in the table and graph below for 1968 and earlier refer to the former commune of Castellet-Saint-Cassien.

Historical population

Year Pop. ±% p.a. 1793 47 —     1800 70 +5.86% 1806 80 +2.25% 1821 56 −2.35% 1831 139 +9.52% 1836 106 −5.28% 1841 89 −3.44% 1846 82 −1.62% 1851 83 +0.24% 1856 90 +1.63% 1861 90 +0.00% 1866 90 +0.00% 1872 86 −0.75% 1876 71 −4.68% 1881 75 +1.10% 1886 74 −0.27% 1891 62 −3.48% 1896 68 +1.86%	Year Pop. ±% p.a. 1901 81 +3.56% 1906 55 −7.45% 1911 50 −1.89% 1921 40 −2.21% 1926 44 +1.92% 1931 41 −1.40% 1936 44 +1.42% 1946 45 +0.22% 1954 37 −2.42% 1962 21 −6.84% 1968 11 −10.22% 1975 52 +24.85% 1982 68 +3.91% 1990 38 −7.02% 1999 48 +2.63% 2007 63 +3.46% 2012 78 +4.36% 2017 87 +2.21%
Source: EHESS and INSEE (1975-2017)

• Communes of the Alpes-de-Haute-Provence department