Aouste (French pronunciation: [aust]) is a commune in the Ardennes department in the Grand Est region of northern France.

Access is by the D36 road from La Férée in the south passing through the village then continuing east to Prez.

The D27 road also comes from Rumigny in the west passing through the commune south of the village and continuing to Marlemont in the south-east.

The Aube river passes through the commune from the east and flows through the village before continuing west to join the Ton at Hannappes.

[3] [3] Argent, a lion of Sable, in chief a bar embattled-counter-embattled of Gules, the whole bordure in Vert.