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 St Marys (SA) statistical area (Lv2) had an estimated population of around 3,185 as of Nov 2025. This reflects an increase of 175 people (5.8%) since the 2021 Census, which reported a population of 3,010 people. The change is inferred from the resident population of 3,134, estimated by AreaSearch following examination of the latest ERP data release by the ABS in June 2024, and an additional 8 validated new addresses since the Census date. This level of population equates to a density ratio of 1,740 persons per square kilometer, which is above the average seen across national locations assessed by AreaSearch. The St Marys (SA) (SA2) saw a growth of 5.8% since the 2021 census, exceeding the SA3 area's growth of 5.0%, 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, released in 2024 with 2022 as the base year. For areas not covered by this data and years post-2032, the SA State Government's Regional/LGA projections by age category are adopted, released in 2023 and based on 2021 data, 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 is projected for the St Marys (SA) (SA2), with the area expected to grow by 617 persons to 2041 based on aggregated SA2-level projections, reflecting a gain of 19.9% in total over the 17 years.

AreaSearch analysis of residential development drivers sees St Marys recording a relatively average level of approval activity when compared to local markets analysed countrywide

AreaSearch analysis of ABS building approval numbers for St Marys shows an average of around 16 new dwelling approvals per year over the past five financial years, totalling an estimated 81 homes. As of FY-26 so far, 2 approvals have been recorded. Each year, on average, 2.4 new residents are gained for each dwelling built between FY-21 and FY-25. The average construction cost value of new homes is $420,000, indicating a focus on the premium market with high-end developments.

This financial year has seen $2.5 million in commercial development approvals, suggesting limited commercial development focus. Compared to Greater Adelaide, St Marys shows 55.0% higher building activity per person, offering buyers greater choice. However, recent periods have seen a moderation in development activity. New building activity comprises 65.0% standalone homes and 35.0% attached dwellings, with a growing mix of townhouses and apartments providing options across different price points.

St Marys has around 353 people per dwelling approval, indicating a developed market. By 2041, St Marys is projected to grow by 633 residents, according to the latest AreaSearch quarterly estimate. Development is keeping pace with projected growth, though buyers may face increasing competition as the population expands.

St Marys has emerging levels of nearby infrastructure activity, ranking in the 31stth percentile nationally

Changes to local infrastructure significantly impact an area's performance. AreaSearch has identified one major project likely affecting this region: Thrive Tonsley - Junction Australia Housing Development, Flinders Medical Centre Southern Redevelopment Stage 1 (Acute Services Building), Springbank Secondary College upgrade, and Tram Grade Separation Projects are key initiatives, with the following projects being most relevant.

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 significant representation in essential services sectors. Its unemployment rate is 3.4%, lower than Greater Adelaide's 3.9%.

In the past year, estimated employment growth was 3.7%. As of September 2025, 1,837 residents are employed, with a participation rate of 67.3% compared to Greater Adelaide's 61.7%, and an unemployment rate 0.6% lower than the regional average. Dominant employment sectors include health care & social assistance, construction, and education & training. Health care & social assistance is particularly notable, with levels at 1.4 times the regional average.

Public administration & safety is under-represented, with only 5.2% of St Marys's workforce compared to Greater Adelaide's 7.4%. The ratio of 0.7 workers per resident indicates local employment opportunities above the norm. Between September 2024 and September 2025, employment increased by 3.7%, labour force grew by 3.4%, and unemployment fell by 0.3 percentage points. In contrast, Greater Adelaide saw employment rise by 3.0% and unemployment fall by 0.1 percentage points. State-level data to 25-Nov-25 shows SA employment grew by 1.19% year-on-year, with the state unemployment rate at 4.0%. National employment forecasts from May-25 project national growth of 6.6% over five years and 13.7% over ten years. Applying these projections to St Marys's employment mix suggests local employment should increase by 7.3% over five years and 15.1% over ten years, though this is a simple extrapolation for illustrative purposes only.

Income levels sit below national averages according to AreaSearch assessment

The suburb of St Marys has a lower income level compared to national averages based on 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, with an average income of $64,830. In comparison, Greater Adelaide's figures are $54,808 and $66,852 respectively. Considering the Wage Price Index growth of 8.8% since financial year 2023, estimated incomes for St Marys would be approximately $57,627 (median) and $70,535 (average) by September 2025. According to Census 2021 income data, household, family, and personal incomes in St Marys rank modestly, between the 35th and 46th percentiles. The earnings profile shows that 34.6% of the population (1,102 individuals) fall within the $1,500 - $2,999 income range, similar to the surrounding region where 31.8% occupy 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 Advantage (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

The dwelling structure in St Marys, as recorded at the latest Census, consisted of 66.3% houses and 33.7% other dwellings (including semi-detached, apartments, 'other' dwellings). This compares to Adelaide metro's figures of 78.8% houses and 21.2% other dwellings. The home ownership rate in St Marys was at 24.6%, with the remaining dwellings either mortgaged (38.6%) or rented (36.8%). The median monthly mortgage repayment in St Marys was $1,654, lower than Adelaide metro's average of $1,992. The median weekly rent figure for St Marys was recorded at $285, compared to Adelaide metro's $335. 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 constitute 62.8 percent of all households, including 28.0 percent couples with children, 23.1 percent couples without children, and 10.4 percent single parent families. Non-family households comprise the remaining 37.2 percent, with lone person households at 31.5 percent and group households making up 5.7 percent of the total. The median household size is 2.4 people, which is smaller than the Greater Adelaide average of 2.6.

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

Educational attainment in St Marys is notably higher than broader benchmarks. Among residents aged 15+, 36.4% hold university qualifications compared to the South Australian (SA) average of 25.7%. In the SA4 region, this figure stands at 28.1%. University graduates make up 24.2%, followed by postgraduate qualifications holders at 9.9%, and graduate diplomas at 2.3%.

Vocational credentials are also prominent, with 29.6% of residents aged 15+ holding such qualifications. Advanced diplomas account for 10.0%, while certificates are held by 19.6%. Educational participation is high, with 30.2% currently enrolled in formal education. This includes tertiary education (9.7%), primary education (8.5%), and secondary education (5.2%).

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

Transport analysis shows 17 active stops operating in St Marys, consisting of bus services. These stops are served by 30 routes, offering a total of 2,213 weekly passenger trips. Transport access is rated good, with residents located an average of 210 meters from the nearest stop.

Service frequency averages 316 trips per day across all routes, equating to around 130 weekly trips per individual stop.

The level of general health in St Marys is notably higher than the national average with prevalence of common health conditions low among the general population though higher than the nation's average across older, at risk cohorts

St Marys shows better-than-average health outcomes with low prevalence of common conditions among its general population, but higher rates are seen among older, at-risk cohorts compared to national averages. Private health cover is held by approximately 53% (~1,676 people) of St Marys' total population, slightly leading the average for SA2 areas, which stands at 59.3% across Greater Adelaide.

Mental health issues and asthma are the most prevalent conditions in St Marys, affecting 8.2% and 6.8% of residents respectively. A total of 72.8% of residents report being completely free from medical ailments, compared to 69.3% across Greater Adelaide. The area has a lower proportion of residents aged 65 and over at 12.1% (385 people), compared to the broader region's 21.2%.

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 level of 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, comprising 43.7% of the population. However, the most notable overrepresentation is in the 'Other' category, which makes up 2.8% of the population compared to 0.8% across Greater Adelaide.

In terms of ancestry, the top three represented groups are English (23.3%), Australian (20.7%), and Other (14.8%). The representation of English is lower than the regional average of 29.9%, while Other is substantially higher than the regional average of 7.3%. There are also notable differences in the representation of certain ethnic groups: Greek (3.3% vs regional 2.5%), Russian (0.5% vs regional 0.3%), and Indian (4.9% vs regional 1.4%).

St Marys's population is younger than the national pattern

At age 34 years, St Mary's median age is lower than Greater Adelaide's average of 39 years and significantly below Australia's median of 38 years. Compared to Greater Adelaide, St Mary's has a higher proportion of residents aged 25-34 years at 20.5%, but fewer residents aged 65-74 years at 5.4%. This concentration of 25-34 year-olds is notably higher than the national average of 14.5%. Between the 2021 Census and the present, the proportion of residents aged 15 to 24 has increased from 11.7% to 13.2%, while those aged 35 to 44 have risen from 16.1% to 17.2%. Conversely, the proportion of residents aged 65 to 74 has decreased from 6.6% to 5.4%, and those aged 55 to 64 have dropped from 10.7% to 9.6%. By 2041, demographic modeling projects significant changes in St Mary's age profile. The 45 to 54 cohort is expected to grow the most at 39%, adding 128 residents to reach a total of 457. Meanwhile, the 65 to 74 cohort is projected to grow by a modest 9%, increasing by 15 people.