Ruy-Montceau (French pronunciation: [ʁɥi mɔ̃so]; before August 2015: Ruy) is a commune in the Isère department in southeastern France.

The Bourbre forms most of the commune's southwestern border.

Population data before 1972 refer to the former commune of Ruy, before the merger with Montceau.

Historical population

Year Pop. ±% p.a. 1793 993 —     1800 947 −0.68% 1806 1,035 +1.49% 1821 1,237 +1.20% 1831 1,278 +0.33% 1836 1,322 +0.68% 1841 1,367 +0.67% 1846 1,331 −0.53% 1851 1,381 +0.74% 1856 1,429 +0.69% 1861 1,396 −0.47% 1866 1,462 +0.93% 1872 1,411 −0.59% 1876 1,320 −1.65% 1881 1,300 −0.30% 1886 1,326 +0.40% 1891 1,329 +0.05% 1896 1,444 +1.67%	Year Pop. ±% p.a. 1901 1,455 +0.15% 1906 1,413 −0.58% 1911 1,339 −1.07% 1921 1,279 −0.46% 1926 1,382 +1.56% 1931 1,514 +1.84% 1936 1,345 −2.34% 1946 1,280 −0.49% 1954 1,340 +0.57% 1962 1,402 +0.57% 1968 1,526 +1.42% 1975 2,184 +5.25% 1982 2,619 +2.63% 1990 3,143 +2.31% 1999 3,762 +2.02% 2007 4,030 +0.86% 2012 4,282 +1.22% 2017 4,529 +1.13%
Source: EHESS and INSEE (1968-2017)

• Communes of the Isère department