St Marys (SA)

Population growth drivers in St Marys are above average based on AreaSearch's ranking of recent, and medium to long-term trends

Based on analysis of ABS population updates for the broader area, and new addresses validated by AreaSearch, the population of the suburb of St Marys (SA) is estimated at around 3,269 as of May 2026. This reflects an increase of 259 people (8.6%) since the 2021 Census, which reported a population of 3,010 people. The change is inferred from the resident population of 3,255, estimated by AreaSearch following examination of the latest ERP data release by the ABS in June 2025, and an additional 10 validated new addresses since the Census date. This level of population equates to a density ratio of 1,786 persons per square kilometer, which is above the average seen across national locations assessed by AreaSearch. The suburb's 8.6% growth since the 2021 census exceeded the SA3 area (5.6%), along with the SA4 region, marking it as a growth leader in the region. Population growth for the area was primarily driven by overseas migration that contributed approximately 79.0% of overall population gains during recent periods.

AreaSearch is adopting ABS/Geoscience Australia projections for each SA2 area, as released in 2024 with 2022 as the base year. For any SA2 areas not covered by this data, and for years post-2032, the SA State Government's Regional/LGA projections by age category, released in 2023 and based on 2021 data, are adopted with adjustments made employing a method of weighted aggregation of population growth from LGA to SA2 levels. Moving forward with demographic trends, an above median population growth of Australian statistical areas is projected, with the area expected to grow by 559 persons to 2041 based on aggregated SA2-level projections, reflecting a gain of 16.7% in total over the 16 years.

Residential development activity is lower than average in St Marys according to AreaSearch's national comparison of local real estate markets

AreaSearch analysis shows St Marys averaged around 16 new dwelling approvals annually over the past five financial years, totalling approximately 80 homes. As of FY-26, four approvals have been recorded. Each year, an average of 2.2 new residents per dwelling was gained between FY-21 and FY-25. The average construction cost value for new homes is $420,000, indicating a focus on the premium market with high-end developments.

In FY-26, $2.5 million in commercial development approvals have been recorded. Compared to Greater Adelaide, St Marys has 52.0% higher building activity per person. The dwelling mix shows 65.0% standalone homes and 35.0% attached dwellings, with a growing variety of townhouses and apartments. There are around 367 people per dwelling approval in St Marys.

By 2041, the population is projected to grow by 545 residents. Development pace is keeping up with projected growth, but increasing competition among buyers is expected as the population expands.

St Marys has emerging levels of nearby infrastructure activity, ranking in the 30thth percentile nationally

Changes to local infrastructure significantly impact an area's performance. AreaSearch has identified one major project likely affecting the region: Thrive Tonsley - Junction Australia Housing Development; others include Flinders Medical Centre Southern Redevelopment Stage 1 (Acute Services Building), Springbank Secondary College upgrade, and Tram Grade Separation Projects. Relevant projects are listed below.

Professional plan users can use the search below to filter and access additional projects.

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Employment conditions in St Marys demonstrate strong performance, ranking among the top 35% of areas assessed nationally

St Marys has an educated workforce with prominent representation in essential services sectors. Its unemployment rate is 3.2%. Over the past year, estimated employment growth was 5.2%, according to AreaSearch's aggregation of statistical area data.

As of December 2025, 1,880 residents are employed while the unemployment rate is 0.6% lower than Greater Adelaide's rate of 3.8%. Workforce participation in St Marys is higher at 71.8%, compared to Greater Adelaide's 66.0%. Census data shows that 10.2% of residents work from home, with Covid-19 lockdown impacts considered. Dominant employment sectors include health care & social assistance, construction, and education & training.

Notably, health care & social assistance has employment levels at 1.4 times the regional average. Public administration & safety is under-represented, with only 5.2% of St Marys' workforce compared to Greater Adelaide's 7.4%. The ratio of 0.7 workers per resident indicates higher local employment opportunities. Over the year to December 2025, employment increased by 5.2% and labour force grew by 4.6%, reducing unemployment by 0.5 percentage points. In contrast, Greater Adelaide saw employment rise by 4.2%, labour force grow by 3.9%, and unemployment fall by 0.3 percentage points. Jobs and Skills Australia's national employment forecasts from May-25 suggest potential future demand in St Marys. National employment is projected to expand by 6.6% over five years and 13.7% over ten years, with varying growth rates across industry sectors. Applying these projections to St Marys' employment mix indicates local employment should increase by 7.3% over five years and 15.1% over ten years, based on a simple weighting extrapolation for illustrative purposes.

Income levels sit below national averages according to AreaSearch assessment

The suburb of St Marys has a lower income level than the national average, according to the latest Australian Taxation Office (ATO) data aggregated by AreaSearch for the financial year 2023. The median income among taxpayers in St Marys is $52,966, and the average income stands at $64,830. In comparison, Greater Adelaide's median income is $54,808, and the average income is $66,852. Based on a 10.17% growth in wages since financial year 2023, as indicated by the Wage Price Index, current estimates for St Marys would be approximately $58,353 (median) and $71,423 (average) as of March 2026. According to the Census conducted in 2021, incomes in St Marys rank modestly, with household, family, and personal incomes all falling between the 35th and 46th percentiles. The earnings profile shows that 34.6% of the population (1,131 individuals) earn within the $1,500 - $2,999 income range, similar to the surrounding region where 31.8% fall into this bracket. Housing affordability pressures are severe in St Marys, with only 83.1% of income remaining after housing costs, ranking at the 34th percentile. The area's Socio-Economic Indexes for Areas (SEIFA) income ranking places it in the fifth decile.

St Marys displays a diverse mix of dwelling types, with a higher proportion of rental properties than the broader region

St Marys' dwelling structures, as per the latest Census, consisted of 66.3% houses and 33.7% other dwellings (including semi-detached, apartments, 'other' dwellings). This contrasted with Adelaide metro's figures of 75.2% houses and 24.9% other dwellings. Home ownership in St Marys was at 24.6%, with mortgaged dwellings at 38.6% and rented ones at 36.8%. The median monthly mortgage repayment in the area was $1,654, higher than Adelaide metro's average of $1,562. Median weekly rent in St Marys was $285, lower than Adelaide metro's $320. Nationally, St Marys' mortgage repayments were significantly lower than the Australian average of $1,863, while rents were substantially below the national figure of $375.

St Marys features high concentrations of group households and lone person households, with a lower-than-average median household size

Family households account for 62.8% of all households, including 28.0% couples with children, 23.1% couples without children, and 10.4% single parent families. Non-family households constitute the remaining 37.2%, with lone person households at 31.5% and group households comprising 5.7%. The median household size is 2.4 people, which is smaller than the Greater Adelaide average of 2.5.

The educational profile of St Marys exceeds national averages, with above-average qualification levels and academic performance metrics

In St Marys, educational attainment is notably high among residents aged 15 and above, with 36.4% possessing university qualifications, surpassing the state average of 25.7% and the SA4 region's 28.1%. The area's strong educational profile is evident in its high proportion of bachelor degree holders (24.2%), followed by postgraduate qualifications (9.9%) and graduate diplomas (2.3%). Vocational credentials are also prominent, with 29.6% of residents holding such qualifications, including advanced diplomas (10.0%) and certificates (19.6%). Educational participation is notably high in the area, with 30.2% of residents currently enrolled in formal education.

This includes 9.7% in tertiary education, 8.5% in primary education, and 5.2% pursuing secondary education.

Transport servicing is good compared to other areas nationally based on assessment of service frequency, route connectivity and accessibility

Transport analysis indicates 17 operational public transport stops in St Marys, serving a mix of bus routes. These stops facilitate 30 individual routes, accommodating approximately 2,213 weekly passenger trips. Transport accessibility is deemed good, with residents typically residing within 210 meters of the nearest stop. Primarily residential, most commuters travel outward from St Marys. Car remains the dominant transport mode at 81%, while bus usage stands at 11%. Vehicle ownership averages 1.2 per dwelling, below regional norms.

According to the 2021 Census, a relatively low 10.2% of residents work from home, potentially due to COVID-19 conditions. Service frequency averages around 316 trips daily across all routes, translating to roughly 130 weekly trips per individual stop.

Health performance in St Marys is lower than average with common health conditions somewhat prevalent across both younger and older age cohorts

St Marys faces significant health challenges, as assessed by AreaSearch's analysis of mortality rates and chronic condition prevalence.

Common health conditions are somewhat prevalent across both younger and older age cohorts. The rate of private health cover is approximately 53% of the total population (~1,720 people), which is higher than the average SA2 area. Mental health issues and asthma were found to be the most common medical conditions in the area, impacting 8.2 and 6.8% of residents respectively. Conversely, 72.8% of residents declared themselves completely clear of medical ailments compared to 67.9% across Greater Adelaide. Health outcomes among the working-age population are broadly typical. The area has 12.5% of residents aged 65 and over (408 people), which is lower than the 19.2% in Greater Adelaide, with national rankings broadly in line with the general population.

St Marys was found to be more culturally diverse than the vast majority of local markets in Australia, upon assessment of a range of language and cultural background related metrics

St Marys has a high cultural diversity, with 35.4% of its population born overseas and 34.9% speaking a language other than English at home. The predominant religion in St Marys is Christianity, accounting for 43.7% of the population. Notably, the 'Other' religious category comprises 2.8% of St Marys' population, compared to 1.8% across Greater Adelaide.

Regarding ancestry, the top three groups are English (23.3%), Australian (20.7%), and Other (14.8%), with the latter being significantly higher than the regional average of 9.7%. Some ethnic groups show notable representation differences: Greek at 3.3% in St Marys versus 2.0% regionally, Russian at 0.5% versus 0.3%, and Indian at 4.9% versus 2.3%.

St Marys's population is younger than the national pattern

St Marys has a median age of 35, which is younger than Greater Adelaide's figure of 39 and slightly below Australia's median age of 38 years. The 25-34 age group is strongly represented in St Marys at 20.2%, compared to Greater Adelaide's percentage. Conversely, the 65-74 cohort is less prevalent in St Marys at 5.3%. This concentration of the 25-34 age group is significantly higher than the national figure of 14.6%. Between 2021 and the present day, the 35 to 44 age group has increased from 16.1% to 17.3% of St Marys' population, while the 85+ cohort has risen from 1.7% to 2.7%. During this period, the 65 to 74 cohort has declined from 6.6% to 5.3%, and the 55 to 64 group has dropped from 10.7% to 9.6%. Looking ahead to 2041, demographic projections indicate significant shifts in St Marys' age structure. Notably, the 45 to 54 group is projected to grow by 32%, adding 112 people and reaching a total of 462 from its previous figure of 349. Meanwhile, the 65 to 74 cohort is expected to grow modestly by 8%, an increase of 13 people.