Barzy-sur-Marne is located some 15 km east by northeast ofChâteau-Thierry and 35 km southwest ofRheims. It can be accessed on the D320 road fromJaulgonne in the west passing through the commune and the village curving south toPassy-sur-Marne. Apart from the village there are two hamlets: Marcilly, and Rosay both located on the D320 road. Some 70% of the commune in the north is heavily forested with the balance consisting of farmland.[3]
The western border of the commune is formed by theMarne river which flows from the south curving west. One small stream south of the village flows into the Marne.[3]
In the 16th century, the people depended on theDuchess of Vendôme. The three separate hamlets composing the village had once each had a port on theMarne to transport stone.
In 1923, the capital of the commune of Barzy-sur-Marne was transferred from Barzy-sur-Marne to the hamlet ofMarcilly, which became the capital of the commune. However, this transfer was done without changing the name of the commune, following the Decree of 23 October 1923.[4]