Bailly-le-Franc (French pronunciation: [baji lə fʁɑ̃]) is a commune in the Aube department in the Grand Est region of north-central France.

The D655 comes from Outines in the north, changing to the D56 at the communal border and passing through the commune then continuing south-west to Chavanges.

[3] The Ruisseau de Chevry flows out of the Étang de Bailly in the west of the commune and passes through the commune towards the east before turning south to form the eastern border of the commune and the department and continuing through the Étang de la Horre to join the Voire.

The Ruisseau du Pré Darras forms the northern border of the commune and the department as it flows east to join the Droye.

The Church of the Exaltation of Saint Croix (16th century) is registered as an historical monument.