St Marys (SA)

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

As per AreaSearch's analysis of ABS population updates and new addresses validated by them, the estimated population of St Marys (SA) as of February 2026 is approximately 3186. This represents an increase of 176 people since the 2021 Census, which reported a population of 3010. The change is inferred from AreaSearch's resident population estimate of 3134 following examination of the latest ERP data release by ABS in June 2024 and validation of seven new addresses since the Census date. This results in a population density ratio of 1741 persons per square kilometer, higher than the average seen across national locations assessed by AreaSearch. St Marys' growth rate of 5.8% since the 2021 Census exceeds the SA3 area's growth rate of 5%, making it a growth leader in the region. Overseas migration contributed approximately 79% of overall population gains during recent periods, driving primary population growth.

AreaSearch adopts ABS/Geoscience Australia projections for each SA2 area, released in 2024 with a base year of 2022. For areas not covered by this data and years post-2032, the SA State Government's Regional/LGA projections by age category are adopted, based on 2021 data and released in 2023, with adjustments made using weighted aggregation methods from LGA to SA2 levels. Based on aggregated SA2-level projections, the suburb of St Marys is expected to grow by an above median rate, gaining 610 persons by 2041, reflecting a total increase of 19.6% over the 17-year period.

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 in St Marys shows an average of around 16 new dwelling approvals per year over the past 5 financial years, totalling an estimated 81 homes. As of FY-26, 2 approvals have been recorded. This averages out to approximately 2.4 new residents per year 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.

In FY-26, $2.5 million in commercial development approvals have been recorded. Compared to Greater Adelaide, St Marys has 55.0% higher building activity per person. The dwelling mix comprises 65.0% standalone homes and 35.0% attached dwellings, including townhouses and apartments across various price points. With around 353 people per dwelling approval, St Marys indicates a developed market.

According to the latest AreaSearch quarterly estimate, St Marys is projected to grow by 626 residents through to 2041, with development keeping pace with projected growth despite increasing competition among buyers due to population expansion.

St Marys has limited levels of nearby infrastructure activity, ranking in the 19thth percentile nationally

Changes in local infrastructure significantly impact an area's performance. AreaSearch has identified one major project expected to influence 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 particularly relevant.

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

Denotes AI-based impression for illustrative purposes only, not to be taken as definitive under any circumstances. Please follow links and conduct other investigations from the project's source for actual imagery. Developers and project owners wishing us to use original imagery please Contact Us and we will do so.

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 3.3%, lower than Greater Adelaide's 3.9%. Employment growth over the past year was estimated at 3.6%.

As of September 2025, 1,832 residents are employed while the unemployment rate is 0.6% below Greater Adelaide's rate. Workforce participation in St Marys is higher at 73.2%, compared to Greater Adelaide's 66.4%. Only 10.2% of residents work from home, a figure potentially impacted by Covid-19 lockdowns. Dominant employment sectors include health care & social assistance, construction, and education & training.

Health care & social assistance is particularly notable with employment levels at 1.4 times the regional average. Public administration & safety, however, is under-represented at 5.2% compared to Greater Adelaide's 7.4%. The ratio of 0.7 workers per resident indicates above-average local employment opportunities. Between September 2024 and September 2025, employment increased by 3.6%, labour force grew by 3.2%, and unemployment fell by 0.3 percentage points in St Marys. In contrast, Greater Adelaide saw employment rise by 3.0%, labour force grow by 2.9%, and unemployment fall by 0.1 percentage points over the same period. Jobs and Skills Australia's national employment forecasts from May-25 project overall employment growth of 6.6% over five years and 13.7% over ten years. Applying these projections to St Marys' employment mix suggests local employment should increase by 7.3% over five years and 15.1% over ten years, though these are simple extrapolations for illustrative purposes and do not account for localized population projections.

Income levels sit below national averages according to AreaSearch assessment

The median income among taxpayers in St Marys suburb was $52,966 according to ATO data aggregated by AreaSearch for financial year 2023. The average income stood at $64,830 during the same period. In comparison, Greater Adelaide's median and average incomes were $54,808 and $66,852 respectively in financial year 2023. Based on Wage Price Index growth of 8.8% since then, estimated current incomes as of September 2025 would be approximately $57,627 (median) and $70,535 (average). Census data from 2021 shows household, family and personal incomes in St Marys rank modestly, between the 35th and 46th percentiles. Income distribution reveals that 34.6% of the population earn within the $1,500 - 2,999 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 suburb's SEIFA income ranking places it in the 5th decile.

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

In St Marys, as per the latest Census, 66.3% of dwellings were houses while 33.7% consisted of other types such as semi-detached homes and apartments. In contrast, Adelaide metro had a higher percentage of houses at 75.2%. The home ownership rate in St Marys was lower 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, exceeding Adelaide metro's average of $1,562. Weekly rent in St Marys stood at $285, lower than Adelaide metro's figure of $320. Nationally, St Marys' mortgage repayments were lower than the Australian average of $1,863, and 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% of all households, including 28.0% couples with children, 23.1% couples without children, and 10.4% single parent families. Non-family households account for 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% holding university qualifications compared to the state average of 25.7%. This figure is also higher than the SA4 region's average of 28.1%, indicating a significant educational advantage for the area. Bachelor degrees are the most common university qualification held by residents at 24.2%, followed by postgraduate qualifications (9.9%) and graduate diplomas (2.3%). Vocational credentials are also prevalent, with 29.6% of residents aged 15 and above holding such qualifications.

This includes advanced diplomas (10.0%) and certificates (19.6%). Educational participation is notably high in St Marys, with 30.2% of residents 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 transport stops operating in St Marys. These stops offer a mix of bus services, with 30 individual routes providing a total of 2,213 weekly passenger trips. Transport accessibility is rated good, with residents typically located 210 meters from the nearest stop. In this primarily residential area, most commuters travel outward. Car remains the dominant mode of transport at 81%, while bus accounts for 11%. Vehicle ownership averages 1.2 per dwelling, below the regional average.

According to the 2021 Census, a relatively low 10.2% of residents work from home, which may reflect COVID-19 conditions. Service frequency averages 316 trips per day across all routes, equating to approximately 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 mortality rates and chronic condition prevalence.

Common health conditions are somewhat prevalent across both younger and older age cohorts. The area has approximately 53% private health cover, which is higher than the average SA2 area (~1,676 people). Mental health issues and asthma were found to be the most common medical conditions, impacting 8.2% and 6.8% of residents respectively. About 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 typical. The area has 12.1% of residents aged 65 and over (385 people), which is lower than the 19.3% in Greater Adelaide. National rankings for health outcomes are 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 level of cultural diversity, with 35.4% of its population born overseas and 34.9% speaking a language other than English at home. Christianity is the main religion in St Marys, 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 1.8% across Greater Adelaide.

In terms of ancestry, the top three represented groups in St Marys are English (23.3%), Australian (20.7%), and Other (14.8%), with the latter significantly higher than the regional average of 9.7%. There are also notable differences in the representation of certain ethnic groups: Greek (3.3% vs 2.0% regionally), Russian (0.5% vs 0.3%), and Indian (4.9% vs 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 Australia's median age of 38 years. The 25-34 age group makes up 19.9% of St Marys' population, higher than Greater Adelaide but lower than the national average of 14.4%. The 65-74 cohort is less prevalent in St Marys at 5.3%. Between 2021 and present, the 15-24 age group has increased from 11.7% to 13.3%, while the 35-44 cohort has risen from 16.1% to 17.3%. Conversely, the 25-34 age group has decreased from 21.2% to 19.9%, and the 65-74 group has dropped from 6.6% to 5.3%. By 2041, demographic projections indicate significant shifts in St Marys' age structure. Notably, the 45-54 group is expected to grow by 37%, reaching 455 people from a base of 331.