Mercedes (Spanish pronunciation: [meɾˈseðes]) is a city in Buenos Aires Province, Argentina. It is located 100 km (62 miles) west from Buenos Aires and 30 km (18 miles) southwest of Luján. It is the administrative headquarters for the district (partido) of Mercedes as well as of the judicial district. The Catedral Basílica de Mercedes-Luján, located in the city, is the seat of the Roman Catholic Archdiocese of Mercedes-Luján.
Mercedes has a population of 51,967 people (51,5% women, 48,5% men) as per the 2001 census [INDEC].