South Australia · Postcode 5231
Millbrook postcode and suburb data
South Australia · Phone area code 08 · 21 km from Adelaide
Suburb snapshot
Millbrook at a glance vs SA
Fast facts and benchmark bars show the suburb's key postcode, Census, SEIFA, school and LGA signals in context.
Quick facts
Benchmarks against SA
Income, rent and SEIFA figures are from the ABS 2021 Census and are reported in 2021 dollars, not adjusted for subsequent inflation.
Where Millbrook ranks: household income sits in the bottom 25% of SA suburbs; SEIFA decile 9 puts it in the top 20% of Australia for socio-economic advantage.
ABS Census 2021 · SEIFA 2021Detailed comparison table
Millbrook vs the SA average and the national average, using population-weighted 2021 Census data.
| Metric | Millbrook | SA avg | AU avg | Greater Adelaide |
|---|---|---|---|---|
| Household income/wk | $1,031 -SA | $1,545 | $1,836 | $1,620 |
| Rent/wk | $250 -SA | $308 | $390 | $329 |
| Mortgage/month | $2,492 +SA | $1,558 | $1,958 | $1,666 |
| Median age | 50 | 45.0 | 45.0 | 42.0 |
| SEIFA decile | 9/10 +SA | 5.0/10 | 6.0/10 | 7.0/10 |
| Unemployment | 4.5% -SA | 6.0% | 5.0% | 6.0% |
Green pill = at least 10% above the SA average; red = at least 10% below; grey = within 10%. For unemployment, colour polarity is inverted: lower is better.
Millbrook is a locality 21 km from Adelaide in South Australia, classified as inner regional by the ABS. The postcode is 5231. It falls within the Adelaide - Central and Hills region. The local government area is Adelaide Hills.
According to the 2021 Census, Millbrook has a population of 133 with a median age of 50. The median weekly household income is $1,031, below the SA average. The unemployment rate is 4.5%, lower than the SA average.
Housing in Millbrook includes a median weekly rent of $250, median monthly mortgage repayment of $2,492, with 50 total dwellings. These housing costs sit above the SA average. Owner-occupied dwellings (owned or mortgaged) make up 83.3% of housing.
On the SEIFA Index of Relative Socio-economic Advantage and Disadvantage, Millbrook scores in decile 9 out of 10, which is well above the national average.
Millbrook is part of the Adelaide Hills statistical area in South Australia.
Millbrook details
Location, Census, housing, SEIFA and geography fields used across this profile.
| Postcode | 5231 |
| State | South Australia (SA) |
| Phone Area Code | 08 |
| Population (2021) | 133 |
| Median Age | 50 years |
| Median Household Income (Census 2021) | $1,031/week |
| Median Personal Income (Census 2021) | $667/week |
| Median Weekly Rent (Census 2021) | $250 |
| Median Monthly Mortgage (Census 2021) | $2,492 |
| Average Household Size | 2.3 persons |
| Area | 11.9 km² |
| Population Density | 11/km² |
| Total Dwellings | 50 |
| Australian Citizens | 88.0% |
| Unemployment Rate | 4.5% |
| SEIFA IRSAD Decile | 9/10 (well above average) |
| Latitude | -34.8350681 |
| Longitude | 138.7998263 |
| Distance from Adelaide | 21 km |
| Region (SA4) | Adelaide - Central and Hills |
| Area (SA3) | Adelaide Hills |
| Local Government | Adelaide Hills |
| Federal Electorate | Mayo |
| State Electorate | Schubert |
| Time Zone | ACST (UTC+9:30), Australia/Adelaide (standard time) |
Age Profile
Show counts
| 0–14 years | 14 (10.5%) |
| 15–24 years | 19 (14.3%) |
| 25–44 years | 22 (16.5%) |
| 45–64 years | 53 (39.8%) |
| 65+ years | 22 (16.5%) |
Housing Tenure
SEIFA socio-economic index
Health Conditions (2021 Census)
| Asthma | 13 (9.8%) |
| Arthritis | 10 (7.5%) |
| Heart Disease | 9 (6.8%) |
| Diabetes | 6 (4.5%) |
| Cancer | 4 (3.0%) |
Long-term health conditions self-reported in the 2021 Census. Persons may report more than one condition.
Motor Vehicles per Dwelling
| No vehicle | 8 (16.7%) |
| 1 vehicle | 5 (10.4%) |
| 2 vehicles | 17 (35.4%) |
| 3+ vehicles | 18 (37.5%) |
Suburbs Near Millbrook
Same Postcode (5231)
More Millbrook Data
Page last reviewed . Data sources: Australian Bureau of Statistics 2021 Census (CC BY 4.0), SEIFA 2021 IRSAD, ACARA school profiles 2025. How this data is sourced.