St Marys
A 21.9% rise in the median house price over one year sits alongside a relatively young, internationally connected population. St Marys has 3,010 residents, a median age of 35, and an overseas-born share of 35.4%, which is 13.8 percentage points above the national figure. University attainment is also high at 47.3%, or 17.2 points above national levels. Compared with nearby Pasadena and Clovelly Park, its compact 1.83 square kilometre footprint and density of 1,643.5 people per square kilometre create a more concentrated suburban setting. The mix of professionals, healthcare workers and overseas migration supports steady demand, while the 36.2% renting share keeps the suburb relevant to both renters and buyers.
Local council: Mitcham
Population
3,010
Median Age
35.0
Household IncomeiMedian weekly household income (ABS Census)
$1,490/wk
DAs (12 months)iDevelopment Applications lodged in the past year
31
Median House
$1.1M
First quarter 2026
St Marys suits buyers seeking established housing close to Adelaide's southern employment and education areas, but the price point requires careful budgeting. Housing is mainly detached at 66.3%, with semi-detached properties at 22.7% and apartments at 11.0%, giving buyers more choice than a purely detached market. Three-bedroom homes account for 48.8% of dwellings, while 4 or more bedrooms represent 19.3%. Mortgage stress is not flagged and the mortgage-to-income measure is 25.6%, although the monthly mortgage figure of $1,654 should be tested against individual borrowing capacity. Affordability improved from 56.2 in 2011 to 50.3 in 2021, but prices are now higher than a year earlier.
For Buyers
St Marys suits buyers seeking established housing close to Adelaide's southern employment and education areas, but the price point requires careful budgeting. Housing is mainly detached at 66.3%, with semi-detached properties at 22.7% and apartments at 11.0%, giving buyers more choice than a purely detached market. Three-bedroom homes account for 48.8% of dwellings, while 4 or more bedrooms represent 19.3%. Mortgage stress is not flagged and the mortgage-to-income measure is 25.6%, although the monthly mortgage figure of $1,654 should be tested against individual borrowing capacity. Affordability improved from 56.2 in 2011 to 50.3 in 2021, but prices are now higher than a year earlier.
For Investors
The rental case rests on a substantial tenant base, limited vacancy and continuing population demand rather than on low entry prices. Renting accounts for 36.2% of households, higher than the 24.7% owned outright, while weekly rent is $285 and vacancy is 5.3%. Rent growth of 33.3% is higher than real income growth of 21.3%, which may support rental returns but can also constrain tenant affordability. The annual growth trend is 1.3% and overseas migration is the primary driver, helping explain ongoing demand in a suburb where 35.4% of residents were born overseas. Development activity recorded 31 applications over 12 months, although visible examples include a two-lot land division, a dwelling alteration and a swimming pool, so investors should not assume a large new dwelling pipeline.
Development Activity
Total DAs
184
Last 12 Months
31
YoY ChangeiYear-over-year change in DA lodgements
+40.9%
Avg DA CostiAverage estimated cost per DA in the past year
N/A
Monthly DA Lodgements
DA Categories
Demographics
St Marys has a younger age profile than Australia overall: the median age is 35, five years below the national comparison. Its overseas-born share is 35.4%, 13.8 percentage points above national levels, while 47.3% hold university qualifications, 17.2 points higher than the national figure. English ancestry is recorded for 928 residents, followed by Other at 590, Scottish at 247, Irish at 200 and Indian at 194. Nepali, Mandarin, Arabic, Punjabi and Malayalam are among the leading listed languages, with counts ranging from 33 to 55. Average household size is 2.4, or 0.1 below the national comparison, while 74.1% of residents stayed at the same address and turnover was 25.9%. This combination of high education, overseas migration and moderate household size supports a socially mixed, relatively mobile population compared with older, lower-density parts of the southern suburbs.
Age Distribution
Bedrooms
Dwelling Structure
66.3%
Houses
22.7%
Townhouse
11.0%
Apartment
Tenure
St Marys is an established market where detached homes remain the main format, but semi-detached and apartment options broaden the entry points. Separate houses make up 66.3% of dwellings, semi-detached homes 22.7% and apartments 11.0%. The bedroom profile is led by 3-bedroom homes at 48.8%, followed by 2-bedroom dwellings at 28.0% and 4 or more bedrooms at 19.3%. Tenure is split between mortgages at 38.2%, renting at 36.2% and outright ownership at 24.7%. Mortgage stress is not flagged, with a mortgage-to-income measure of 25.6%, while rent-to-income is 19.1%. The latest price is therefore higher than the previous year even though affordability is described as improving.
Mortgage / mo
$1,654
Rent / wkiABS Census 2021 median across all dwelling types. Current market rents are typically higher.
$285
Census 2021
HH Size
2.4
Personal Income / wk
$785
Vacancy Ratei% of dwellings unoccupied on Census night (ABS 2021)
5.3%
Unoccupied
70
Rent / IncomeiMedian rent as % of household income. Over 30% = housing stress
19.1%
Mortgage / IncomeiMedian mortgage as % of household income. Over 30% = housing stress
25.6%
Community Profile
Languages Spoken at Home
Ancestry
Household Composition
43.6%
Couples with children
36.9%
Couples, no children
16.7%
Single parent
795
Total families
Economy & Employment
Employment in St Marys is anchored by service industries, especially healthcare, which accounts for 29.2% of industry employment and 336 workers. Education represents 10.3% and 119 workers, followed by construction at 8.7% and 100, professional and technical services at 7.0% and 80, and public administration at 6.1% and 70. The occupation mix reinforces this structure, with 435 professionals, 237 community and personal service workers, 212 trades workers, 168 managers and 163 clerical and administrative workers. The labour force participation rate is 67.5%, unemployment is 6.1% and the full-time employment rate is 55.6%. Household income sits at $1,490 per week, around the 46.6 percentile, so earnings are close to the middle rather than clearly above average. Healthcare employment is more than double the education share, giving the local economy a stronger care and service orientation than a construction-led profile.
Unemployment
6.1%
Labour Force
1,696
Unemployed
104
Source: ABS Census 2021
Socio-Economic Indexes (SEIFA)iABS index ranking suburbs from 1 (most disadvantaged) to 10 (most advantaged)
Full-time
55.6%
Part-time
39.4%
Participation
67.5%
Employed
1,592
Full-time and part-time are shares of the employed. Source: ABS Census 2021
Occupations
Top Industries
University
47.3%
Postgraduate
13.7%
Born Overseas
35.4%
Dwellings
1,250
Transport to Work
Daily mobility is strongly car based, with 73.5% driving to work compared with 7.4% using public transport, 2.5% walking or cycling and 10.9% working from home. That pattern means access to employment, shopping and services is likely to be easiest for households with a vehicle, while public transport users should compare routes and travel times carefully. At 1,643.5 people per square kilometre across 1.83 square kilometres, St Marys is more concentrated than a low-density outer suburb. Recorded crime totalled 237 incidents, equivalent to 78.7 per 1,000 residents, so street-level conditions and household security remain important considerations. Families should check enrolment zones, nearby government and non-government school options, and travel times against the exact address because school access can vary across local boundaries. A median age of 35 and average household size of 2.4 support a mix of young households, families and established residents rather than a predominantly senior population.
Drive
73.5%
Public Transport
7.4%
Walk / Cycle
2.5%
Work from Home
10.9%
Growth Outlook
Growth is steady rather than speculative. The forecast annual trend is 1.3%, with overseas migration identified as the primary driver, while the shift trajectory is Stable. Population change across the wider area is 18.3% over 10 years, indicating sustained expansion without a sharply accelerating trajectory. Rent growth of 33.3% is higher than real income growth of 21.3%, which can increase investor interest but also place pressure on household budgets. The core gentrification assessment gives St Marys a score of 18 and a stage of Not gentrifying, although a separate shift measure records a score of 41 and Early signs. Taken together, these indicators point to gradual demographic and market change rather than a full redevelopment cycle. The suburb's established status, compact footprint and overseas migration base should continue to support demand, while the Stable trajectory suggests change will be incremental compared with faster-transforming markets.
Population trend: Mitcham council area
St Marys sits in the Mitcham council area. These are the council area's residents, not St Marys's.
Residents 2025
71,267
Growth, 5 yr average
+0.9%/yr
2020 to 2025
Growth, last year
+1.0%
2024 to 2025
ABS Estimated Resident Population by LGA, 30 June each year; council area, not this suburb
Safety & Crime
Total Offences
237
Year ending June 2024
Rate per 1,000 People
78.7
Source: Crime Statistics Agency Victoria / SA Police
National Ranking iPercentile rank among ~15,000 AU suburbs. 90% = higher than 90% of suburbs
How St Marys compares to ~15,000 Australian suburbs
Frequently Asked Questions
Is St Marys a good suburb to live in?
St Marys can suit households wanting an established southern suburb with a median age of 35, a 36.2% renting share and a compact 1.83 square kilometre footprint. Car access is important because 73.5% drive to work, compared with 7.4% using public transport.
What schools are in St Marys?
School choices should be checked using the exact address, including enrolment zones, nearby government and non-government options, and travel times. Household needs may vary in a suburb where 48.8% of dwellings have 3 bedrooms and 43.6% of families are couples with children.
Is St Marys safe?
St Marys recorded 237 crime incidents, equal to 78.7 incidents per 1,000 residents. That rate is a useful local risk indicator, but safety can vary by street and time, so buyers and renters should inspect the exact location and consider lighting, access and security.
Is St Marys good for property investment?
St Marys has a 36.2% renting share, weekly rent of $285 and a 5.3% vacancy rate. The annual growth trend is 1.3%, overseas migration is the main driver and 31 development applications were recorded over 12 months, so investors should assess yield, property type and local competition carefully.
How is St Marys's population changing?
The suburb has 3,010 residents today, while population change across the wider area is forecast at 18.3% over 10 years. Growth is running at 1.3% annually and is primarily driven by overseas migration. The trajectory is Stable, with a gentrification score of 18 and a Not gentrifying stage.
How to read these comparisons
Phrases like "above the national average" reference the unweighted median across Australian suburbs with more than 1,000 residents, not population-weighted national figures. Suburb-level medians are more useful for ranking suburbs against each other; ABS census headlines are population-weighted (so dominated by Sydney and Melbourne) and can read very differently.
Current baseline (refreshed 2026-05-10): median age 40, university-educated 30.1%, born overseas 21.6%, average household size 2.5 people.
Data sources: ABS 2021 Census (demographics, income, tenure), SA Department for Housing and Urban Development (house prices), state education open registers (school locations), state Crime Statistics agencies (offences), council DA portals (development applications).
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