Osmoy-Saint-Valery is a commune in the Seine-Maritime department in the Normandy region in north-western France.

A farming village situated by the banks of the river Béthune in the Pays de Bray at the junction of the D 1 and the D 77 roads, some 15 miles (24 km) southeast of Dieppe.

Commune created in 1823 by the fusion of the three communes of Maintru, Osmoy and Saint-Valery-sous-Bures.

Historical population

Year Pop. ±% p.a. 1793 133 —     1800 135 +0.21% 1806 150 +1.77% 1821 154 +0.18% 1831 607 +14.70% 1836 610 +0.10% 1841 616 +0.20% 1846 613 −0.10% 1851 572 −1.37% 1856 542 −1.07% 1861 526 −0.60% 1866 504 −0.85% 1872 464 −1.37% 1876 505 +2.14% 1881 520 +0.59% 1886 477 −1.71% 1891 486 +0.37% 1896 478 −0.33%	Year Pop. ±% p.a. 1901 419 −2.60% 1906 450 +1.44% 1911 441 −0.40% 1921 413 −0.65% 1926 442 +1.37% 1931 415 −1.25% 1936 420 +0.24% 1946 433 +0.31% 1954 400 −0.99% 1962 360 −1.31% 1968 324 −1.74% 1975 332 +0.35% 1982 293 −1.77% 1990 299 +0.25% 1999 310 +0.40% 2007 331 +0.82% 2012 336 +0.30% 2017 324 −0.72%
Source: EHESS and INSEE (1968–2017)

• The church of Notre-Dame, dating from the twelfth century.
• The chapel at Maintru.
• A sixteenth-century stone cross.
• The manorhouse de La Valouine, built in 1602 by the seigneurs de Ricarville.

• Communes of the Seine-Maritime department