Eustache Charles Joseph d'Aoust (27 February 1763, Douai – 2 July 1794, Paris) was a general officer during the French Revolutionary Wars.

He was provisionally appointed general of division by representatives Joseph Fabre and Reymond Gaston on 7 August and assumed command of the camp near Perpignan.

The Spanish army captured the Fort de Bellegarde, a major fortress, when the siege ended on 24 June.

To make matters worse, the Spanish commander Captain General Antonio Ricardos was a capable opponent.

Believing that Ricardos' Spanish army was unstoppable, Hilarion Paul de Puget-Barbantane moved his headquarters well to the rear on 4 September 1793, putting d'Aoust in charge of Perpignan.

Other French troops under Jacques Gilles Henri Goguet attacked Peyrestortes hill, where Jerónimo Girón-Moctezuma, Marquis de las Amarilas deployed his division.

A few days after the French defeat at the Battle of Truillas on 22 September, Dagobert was arrested and d'Aoust became the army commander.

On 3 October, d'Aoust with 16,000 men engaged Ricardos and 15,000 Spanish troops at Le Boulou on the Tech River.