Singleton is a town on the banks of the Hunter River in New South Wales, Australia. Singleton is 202km north-north-west of Sydney, and 70 km …Singleton is a town on the banks of the Hunter River in New South Wales, Australia. Singleton is 202km north-north-west of Sydney, and 70 km north-west of Newcastle. At June 2018, Singleton had an urban population of 16,346.