Blakiston is a town in the Australian state of South Australia. The town is located approximately 36 kilometres (22 mi) south-east of the state capital of Adelaide, adjacent to the Princes Highway. Its postal code is 5250 – though it has no post office. Post is delivered to the neighbouring town of Littlehampton which shares the post code. The town and surrounding countryside, a mixture of pastureland and eucalypt forest, make up around 16 square kilometres. At the 2021 census, the locality of Blakiston had a population of 377 and a median age of 46.