Gretna is a rural locality in the local government areas (LGA) of Central Highlands and Derwent Valley in the Central and South-east LGA regions of Tasmania.

[4] Macquarie Plains Post Office opened in 1932 and was renamed Gretna in 1907.

[5] The River Derwent forms the south-western and part of the southern boundaries of the locality.

The C181 route (Marked Tree Road) runs north through the locality to meet the B110 route (Hollow Tree Road) in the locality of Hollow Tree, and the C183 route (Bluff Road) runs north-east to Elderslie.

Gretna is the location of three heritage listed locations, all of which were listed on the Register of the National Estate before its removal and along with 5 other properties are on the Tasmanian Heritage Register to this day.