Bahía Blanca is a city by the Atlantic Ocean, in the southwest province of Buenos Aires, Argentina. It is the seat of government of the Bahía Bl…Bahía Blanca is a city by the Atlantic Ocean, in the southwest province of Buenos Aires, Argentina. It is the seat of government of the Bahía Blanca Partido, with 301,572 inhabitants according to the 2010 census. Bahía Blanca is the principal city in the Greater Bahía Blanca area.