Thornlie, WA
By Lauren McCaleb · Reviewed by Dylan Duncan ·
Thornlie is a large residential suburb of Perth, about 15 km south-east of the city centre within the City of Gosnells, with the Canning River running along its northern side. Before European settlement the area would have been used by the local Noongar people. Captain Peter Pégus was granted land here in 1829, calling his holding Coleraine, though his settlement ended after a fire in the 1830s. The suburb's name comes from Thornlie Park, a farm established in 1884 by Frank and Amy James and later run as a productive dairy. After the large estate was auctioned in the 1950s, Thornlie developed as a residential area aimed at middle-income buyers, and is often described as one of Perth's leafy suburbs for its generous block sizes. It is also home to Crestwood, a model housing estate that won national and international recognition in the 1970s as a rare and well-preserved example of Radburn design, in which homes face parkland and pedestrian paths are separated from roads.
Less advantaged than the national average
Thornlie is more socio-economically advantaged than about 33% of the 14,462 Australian suburbs we score, based on the ABS SEIFA index (raw score 958, where about 1000 is the national average).
A socio-economic measure from ABS Census data — not a measure of how good a suburb is to live in or visit. How we calculate this.
Thornlie at a glance
- Population (2021)
- 23,665
- Median age
- 38
- Median weekly household income
- $1,571
- SEIFA score
- 958
- Coordinates
- -32.0614, 115.9577
Thornlie demographics (2021 Census)
The figures below profile Thornlie using the Australian Bureau of Statistics 2021 Census; every percentage is a share of a clearly stated Census count, so each one traces back to the source. At a glance, the largest age group is young adults (25–44) at 27%, 21% of homes are rented, and 43% of residents were born overseas.
Age profile
| Age group | People | Share |
|---|---|---|
| Children (0–14) | 4,605 | 19% |
| Youth (15–24) | 2,888 | 12% |
| Young adults (25–44) | 6,339 | 27% |
| Mid-life (45–64) | 5,828 | 25% |
| Seniors (65+) | 4,005 | 17% |
Share of the 23,665 people counted by age.
Housing and households
| Tenure | Dwellings | Share |
|---|---|---|
| Owned outright | 2,795 | 33% |
| Owned with a mortgage | 3,578 | 43% |
| Rented | 1,775 | 21% |
| Dwelling type | Dwellings | Share |
|---|---|---|
| Houses | 7,654 | 91% |
| Townhouses & semis | 642 | 8% |
| Flats & apartments | 104 | 1% |
Tenure and dwelling shares are of the roughly 8,406 occupied private dwellings in Thornlie.
- Median weekly rent
- $330
- Median monthly mortgage
- $1,625
- Average household size
- 2.7 people
- Median weekly family income
- $1,825
- Median weekly personal income
- $682
Community and culture
- Born overseas
- 9,859 (43%)
- Speaks a language other than English at home
- 7,270 (32%)
- Aboriginal and/or Torres Strait Islander
- 562 (2%)
Work and education
- Completed Year 12
- 10,127 (55%)
- Labour-force participation
- 61.8%
- Unemployment rate
- 7.1%
- Employed full-time
- 6,501
- Employed part-time
- 3,844
Source: ABS Census of Population and Housing, 2021 (General Community Profile, by Suburb and Locality). © Australian Bureau of Statistics, released under CC BY 4.0. How we group bands and derive each share is set out on our methodology page.
Weather and climate in Thornlie
Based on 2014–2023 records, the warmest month in Thornlie is January (average daytime high around 31.2°C) and the coolest is July (around 15.5°C). The area receives roughly 739 mm of rain across the year.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 31.2°C | 17.4°C | 23 mm |
| Feb | 30.6°C | 17.5°C | 24 mm |
| Mar | 27.8°C | 16.5°C | 43 mm |
| Apr | 23.3°C | 13.6°C | 45 mm |
| May | 19.2°C | 10.8°C | 81 mm |
| Jun | 16.5°C | 9.2°C | 103 mm |
| Jul | 15.5°C | 8.7°C | 140 mm |
| Aug | 16.2°C | 8.3°C | 122 mm |
| Sep | 18.2°C | 9.2°C | 69 mm |
| Oct | 21.3°C | 10.9°C | 49 mm |
| Nov | 25.5°C | 13.3°C | 30 mm |
| Dec | 29.4°C | 15.8°C | 10 mm |
Climate normals, 2014–2023 (Open-Meteo, ERA5 reanalysis).
Common questions about Thornlie
Where is Thornlie?
Thornlie is a suburb of Western Australia, Australia.
What is the population of Thornlie?
At the 2021 Census, Thornlie had a population of about 23,665.
Is Thornlie an advantaged area?
Thornlie has an ABS SEIFA score of 958, where about 1000 is the national average — higher scores indicate greater relative socio-economic advantage. That gives it a Suburb Score of 33 out of 100 — more socio-economically advantaged than about 33% of Australian suburbs.
What is the weather like in Thornlie?
Thornlie has average daytime highs of about 22.9°C and overnight lows of about 12.6°C, with roughly 739 mm of rain across the year (based on 2014–2023 climate normals).
How big is Thornlie?
Thornlie is one of the most populous suburbs in Western Australia — the 5th-largest by usual resident population at the 2021 Census (about 23,665 usual residents).
Where Thornlie ranks
Thornlie appears in these data-driven guides — each a transparent sort on a single ABS figure shown on this page.
Nearby suburbs in Western Australia
More suburb guides in Western Australia
Other hand-written, cited guides — browse all guides.