The Tamar River in northern Tasmania is formed by the merging of the North Esk River and South Esk Rivers in Launceston. Named for the River Tamar in Cornwall, UK, the Tamar flows north for approximately 70 km into Bass Strait at Port Dalrymple .

Although there are several bridge crossings in Launceston, these are across the Esk rivers; there are none across the Tamar in the city itself. The only Tamar bridge crossing is the Batman Bridge, a spectacular bridge in the relatively remote area of Sidmouth , around half way up the river.