Wanniassa (/ˈwɒnɪæsə/) (postcode 2903) is a suburb in Australia's capital, Canberra: more specifically, in the city's southern district of Tuggeranong.

The Wanniassa Shops is a smaller retail centre located at the north of the suburb, housing a Coles supermarket and various other businesses including a butcher, a baker and local take-aways.

The facilities in the Active Leisure Centre, available for student use, include a 25-metre swimming pool and fully equipped gym.

Erindale College is well known for its sporting program (talented sports program) which has produced many professional athletes such as Huia Edmonds, Brent Kite, Jason Smith, Brett Finch, Michael Weyman, David Atkins, Joel Monaghan, Royston Lightning, Allan Brookman, Michael Robertson, Nathan Smith, Andrew Price, Ben Rauter, Michael Dobson, David Palavi and Brenton Lawrence.

[13] St Matthew's Anglican Church is located adjacent to Trinity Christian School on Laurens Street.

Christian City Church Tuggeranong offers services at the hall of Wanniassa School Senior Campus while they await the construction of a more permanent building in Monash.

[19][20][21][22] Wanniassa is underlain by Deakin Volcanics from the Silurian age 414 million years old – cream-green and purple rhyodacite in the eastern half, with tuff, agglomerate and rhyolite in the west.

[23] Gardeners have to deal with a high proportion of clay soils leading to poor drainage which can be a problem, especially for those in the hillier parts of the suburb.