Saint-Didier (French pronunciation: [sɛ̃ didje]; Breton: Sant-Ider; Gallo: Saent-Didier) is a commune in the Ille-et-Vilaine department in Brittany in northwestern France.

Inhabitants of Saint-Didier are called déodatiens in French.

Historical population

Year Pop. ±% p.a. 1793 1,226 —     1800 1,023 −2.55% 1806 1,030 +0.11% 1821 1,159 +0.79% 1831 1,134 −0.22% 1836 1,106 −0.50% 1841 1,104 −0.04% 1846 1,048 −1.04% 1851 1,055 +0.13% 1856 1,000 −1.07% 1861 980 −0.40% 1866 920 −1.26% 1872 881 −0.72% 1876 871 −0.28% 1881 841 −0.70% 1886 833 −0.19% 1891 822 −0.27% 1896 815 −0.17%	Year Pop. ±% p.a. 1901 848 +0.80% 1906 853 +0.12% 1911 790 −1.52% 1921 725 −0.85% 1926 689 −1.01% 1931 697 +0.23% 1936 682 −0.43% 1946 691 +0.13% 1954 693 +0.04% 1962 679 −0.25% 1968 652 −0.67% 1975 679 +0.58% 1982 859 +3.42% 1990 1,055 +2.60% 1999 1,275 +2.13% 2007 1,636 +3.17% 2012 1,884 +2.86% 2017 2,052 +1.72%
Source: EHESS and INSEE (1968-2017)

• Communes of the Ille-et-Vilaine department

• Base Mérimée: Search for heritage in the commune, Ministère français de la Culture. (in French)
• Mayors of Ille-et-Vilaine Association (in French)