Killarney is a rural town and locality in the Southern Downs Region, Queensland, Australia. It borders New South Wales. In the 2021 cen…Killarney is a rural town and locality in the Southern Downs Region, Queensland, Australia. It borders New South Wales. In the 2021 census, the locality of Killarney had a population of 918 people. Killarney is located 35 kilometres south-east of Warwick on the Condamine River in the Darling Downs. Killarney is located about 8 kilometres from the Queensland/New South Wales border. It is close to Queen Mary Falls in the Main Range National Park, where Spring Creek plunges 40 metres into the valley.