Necochea is a port and beach city situated in the southwest region of Buenos Aires Province, Argentina. It is positioned on the Atlantic Coast at the mouth of the Quequén Grande River, located approximately 528 km (328 mi) from the capital city of Buenos Aires and 120 km (75 mi) southwest of Mar del Plata.
The city serves as the seat of government for Necochea Partido. According to the 2010 census conducted by INDEC, the city proper has a population of 90,000 inhabitants.