The Flinders River is the longest river in Queensland, Australia, at approximately 1,004 kilometres. It was named in honour of the explorer Matthew Flinders. The catchment is sparsely populated and mostly undeveloped. The Flinders rises on the western slopes of the Great Dividing Range in North West Queensland and flows generally north …The Flinders River is the longest river in Queensland, Australia, at approximately 1,004 kilometres. It was named in honour of the explorer Matthew Flinders. The catchment is sparsely populated and mostly undeveloped. The Flinders rises on the western slopes of the Great Dividing Range in North West Queensland and flows generally north-west through the Gulf Country, across a large, flat clay pan, before entering the Gulf of Carpentaria.