Grand-Puy-Lacoste is located in the Pauillac terroir, one of the six common appellations of the Medoc along the left bank of the Gironde. The Pauillac appellation is limited to the municipal district of 2,274 hectares. It boasts 18 properties classified in 1855 (about 85% of the appellation's total production). The commune is separated from Saint-Estèphe in the north by the marshy area of Breuil and from Saint-Julien in the south by the hollow formed by the stream Juillac. The Grand-Puy plateau is located to the west of the village, above the hamlet of Bages. This offshoot of the grounds (called a "puy" in the old local dialect)
