GEELONG, a town of South Australia, Victoria colony, Grant county, at the head of Geelong harbour, the western arm of the bay of Port Philip, 40 miles S.W. of Melbourne. Since the discovery in 1851 of the gold fields at Ballarat, 40 miles N.N.W. of Geelong, this town has rapidly risen into importance. It is situated in a very pleasant and fertile district, adorned with numerous cottages and gardens, and the climate is mild and salubrious. The town is built on the harbour of Corio, by means of which a great trade is carried on. Large vessels discharge their cargoes into lighters six miles below the town. Pop. (1853) about 20,000.