Murdunna is a small town in south-east Tasmania, Australia at the head of King George Sound, a narrow bay opening off Norfolk Bay. Murdunna is approximately halfway down the Forestier Peninsula on the Arthur Highway to Port Arthur. It is around 6 metres (20 feet) above sea level. At the 2006 census, Murdunna had a population of 321.
Population increases in the summer months, and it is becoming increasingly popular with people from Hobart who are looking for weekend getaways. Many houses are owned by non-residents who use them as holiday homes. The name Murdunna is believed to come from a local indigenous word meaning "place of the stars".
Tourism is a major source of income, although forestry was and still continues to be a major employer. Many inhabitants commute to Hobart on a daily basis with improved roads.
Recreation is centered on Sommers Bay, about 5 km (3.1 mi) west of Murdunna itself.
Murdunna Post Office opened on 1 June 1910 and closed in 1969.