Bahía Blanca (bäē`ä bläng`kä), city (1991 pop. 255,145), Buenos Aires prov., SE Argentina, a port near the head of the Bahía Blanca, an inlet of the Atlantic Ocean. It is the main commercial center and principal shipping point of the southern Pampa, as well as a rail terminus and an industrial city. A huge import trade is also carried on. Founded as a fortress town in 1828, Bahía Blanca grew with the economic expansion of the southern Pampa in the early 20th cent. The Bernardino Rivadavia library, founded in 1882, is a city landmark. A perochemical complex was built at Bahía Blanca during the late 1970s and early 1980s.