Pont-Saint-Martin (French pronunciation: [pɔ̃ sɛ̃ maʁtɛ̃] ; Breton: Pont-Marzhin) is a commune in the Loire-Atlantique department in western France.

Legend has it that Saint Martin built a bridge over the river Ognon on the territory of the commune.

The parish was established in the sixth century by Saint Martin, who was charged with preaching in the region by the bishop of Nantes. It is first mentioned in a bull of Pope Alexander III in 1179. Under the supervision of the monastery of Villenuve and convent of Couëts, 250 hectares were planted in vineyards.

During the Vendéan Wars (1793-1794), the commune lost 18 percent of its population.

Historical population

Year Pop. ±% p.a. 1793 1,698 —     1800 982 −7.52% 1806 1,281 +4.53% 1821 395 −7.54% 1831 1,478 +14.11% 1841 1,604 +0.82% 1846 1,780 +2.10% 1851 1,955 +1.89% 1856 1,906 −0.51% 1861 1,851 −0.58% 1866 1,648 −2.30% 1872 1,679 +0.31% 1876 1,717 +0.56% 1881 1,723 +0.07% 1886 1,734 +0.13% 1891 1,694 −0.47% 1896 1,641 −0.63% 1901 1,635 −0.07%	Year Pop. ±% p.a. 1906 1,602 −0.41% 1911 1,543 −0.75% 1921 1,429 −0.76% 1926 1,515 +1.18% 1931 1,471 −0.59% 1936 1,425 −0.63% 1946 1,516 +0.62% 1954 1,713 +1.54% 1962 1,932 +1.52% 1968 2,134 +1.67% 1975 2,690 +3.36% 1982 3,320 +3.05% 1990 3,835 +1.82% 1999 4,754 +2.42% 2007 5,454 +1.73% 2012 5,658 +0.74% 2017 6,037 +1.31%
Source: EHESS and INSEE (1968-2017)

It is twinned with the Hampshire village of Brockenhurst in England.

• Communes of the Loire-Atlantique department