The Marne is a river in France, a right tributary of the Seine in the area east and southeast of Paris. It is 514 kilometres (319 mi) long. The river gave its name to the départements of Haute-Marne, Marne, Seine-et-Marne, and Val-de-Marne.

The Marne starts in the Langres plateau, runs generally north then bends west between Saint-Dizier and Châlons-en-Champagne, joining the Seine at Charenton just upstream from Paris. In the Champagne région, part of the water is led through the artificial lake Lac du Der-Chantecoq, in order to regulate the water discharge. This way, large inundations or low river levels downstream are prevented.

The Marne is infamous as the site of the eponymous two battles during the First World War. The first battle was a turning point of World War I, fought in 1914. The second battle was fought four years later, in 1918.

During the 19th and 20th centuries, the Marne inspired many painter artists among whom:

the war was also in this river in 1918 the battle of amiens..........................................................