Weeroona Island (formerly known as Port Flinders) is a locality in the Australian state of South Australia about 209 kilometres (130 mi) north of the state capital of Adelaide and about 9.5 kilometres (5.9 mi) northeast of the city of Port Pirie. The locality consists of an outcrop of land which is surrounded by low lying land that can be subject to inundation at high tide and which is connected to the Augusta Highway in the east by a causeway.