Ballay is located some 35 km east by south-east ofRethel and 3 km north ofVouziers. Access to the commune is by the D977 road from Vouziers which passes through the centre of the commune and the village and continues north toQuatre-Champs. The D19 road from Quatre-Champs toVandy forms part of the northern border of the commune. Apart from the village there are the hamlets of Claire-Fontaine, Landèves, and La Noue Adam. The commune is mostly forested in the east and west with farmland down the centre.[3]
TheAisne river forms the south-western border of the commune as it flows north to eventually join theOise atClairoix. TheFournelles flows through the centre of the commune from the north and joins the Aisne on the south-western border. Several tributaries rise in the commune and feed the Fournelles including theMartignère, theRuisseau du Moulin des Bois, and theChalan which forms part of the southern border of the commune.[3]
Clairefontaine and Landèves were municipalities in 1790 and merged into Ballay at the end of 1790.
In the 12th century Ballay was a lordship with a castle and a parish with a church dedicated to Notre-Dame which was an annex toVandy. AnAugustinian Priory, Notre-Dame of Landèves, was founded at Landèves in 1219 by two brother lords of Bally who made it religious. Since its foundation the priory served the parish of Ballay. The priory became an abbey in 1623. The abbey and church were destroyed during theFrench Revolution.