Petorca is a Chilean province, being the most extensive of the Valparaiso Region, besides being the northernmost. It limits to the north with the Province of Choapa. To the south with the Province of Valparaíso and the Province of Quillota. To the east with the Province of San Felipe de Aconcagua. And to the west with the Pacific Ocean. It has an area of 4588.9 km² and has a population of 78 299 inhabitants. Its provincial capital is the city of La Ligua.