Bernos-Beaulac is a commune in the Gironde department in Nouvelle-Aquitaine in southwestern France. The principal settlement in the commune is the village of Beaulac, situated where the route nationale 524 crosses the Ciron river. The RN 524 forms part of the Itinéraire à Grand Gabarit, a route which has been modified to allow its use by the oversize road convoys conveying body sections and wings of the Airbus A380 airliner.