The Tasmanian temperate rain forests are a temperate broadleaf and mixed forests ecoregion in western Tasmania. The ecoregion is part of the Australasian realm, which includes Tasmania and Australia, New Zealand, New Guinea, New Caledonia, and adjacent islands.

Rainforest communities in Australia are classified as closed forests in which the canopy comprises 70–100% cover. It can be divided into tropical, subtropical, monsoon and temperate rainforest. Tasmanian rainforest is classified and as cool temperate rainforest, it represents the most floristically complex and best developed form of this forest type in Australia. In Tasmania, they can be found in the West, Savage River National Park, South West, North East and in patches on the East Coast. On the mainland of Australia, cool temperate rainforest have a wide variety of woodland trees, but Tasmania only has a limited number of woodland and vascular plants such as mosses, liverworts, lichen and fungi. Because of this, the definition of Tasmanian cool temperate rainforest was redefined in the 1980s to allow for communities that did not meet the canopy requirements and clearly separate cool temperate rainforest from mixed forest; The current definition states that cool temperate rainforests are those with trees usually greater than 8 m (26 ft) in height and capable of regenerating in the absence of large scale catastrophic events, such as fire. These forests are climax vegetation and are dominated by angiosperms such as Nothofagus cunninghamii (myrtle beech), Atherosperma moschatum (sassafras), and Eucryphia lucida (leatherwood) as well as gymnosperms such as Athrotaxis selaginoides (King Billy Pine), Lagarostrobos franklinii (huon or macquarie pine) and Phyllocladus aspleniifolius (celery-top pine). The limited number of woody species is thought to be due to repeated glaciation.

Tasmanian cool temperate rainforest can be divided into four types: Callidendrous rainforest, Thamnic rainforest, Implicate rainforest and Open Montane. These four major types differ in many of their characteristics such as structure, floristics, distribution, level of endemism and ecology.