Bahía Blanca is a city in eastern Argentina in Buenos Aires Province and a seaport at the head of the Bahía Blanca ('White Bay' - an arm of the Atlantic Ocean).

The leading city of eastern Argentina, Bahía Blanca is an important trans-shipping and commercial center, handling the large export trade in grain and wool from southern Buenos Aires Province, oil from Neuquén Province, and fruit from the Río Negro Valley. The National University of the South (Universidad Nacional del Sur) (1956) is in Bahía Blanca. The city was founded as a fort in 1828 and became commercially important after the construction of a railroad through the area in 1885. Population (1991) 260,096.