Thornleigh

An assessment of population growth drivers in Thornleigh reveals an overall ranking slightly below national averages considering recent, and medium term trends

Thornleigh's population is estimated at around 9,330 as of Feb 2026, reflecting an increase of 432 people since the 2021 Census which reported a population of 8,898. This growth is inferred from AreaSearch validation of new addresses and latest ERP data released by ABS in June 2024. The population density is 2,410 persons per square kilometer, placing Thornleigh in the upper quartile nationally according to AreaSearch assessments. Thornleigh's 4.9% growth since census compares within 2.9 percentage points of NSW's state average of 7.8%. Overseas migration contributed approximately 91.0% of population gains recently. AreaSearch uses ABS/Geoscience Australia projections for each SA2 area, released in 2024 with a base year of 2022, and NSW State Government's SA2 level projections for areas not covered by this data, released in 2022 with a base year of 2021.

These projections anticipate lower quartile growth nationally, with Thornleigh expected to increase by 203 persons to 2041, reflecting a gain of 0.5% over the 17 years.

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

Based on AreaSearch analysis of ABS building approval numbers, allocated from statistical area data, Thornleigh has averaged around 29 new dwelling approvals annually over the past five financial years. This totals an estimated 147 homes. So far in FY-26, 3 approvals have been recorded. On average, 1.1 new residents arrive per year per new home over the past five financial years (between FY-21 and FY-25), indicating balanced supply and demand with stable market conditions. However, recent figures show an acceleration to 8.4 people per dwelling over the past two financial years, suggesting increasing demand and tightening supply.

Development projects average $741,000 in construction value, targeting the premium market segment with higher-end properties. This year has seen $10.3 million in commercial approvals registered, indicating balanced commercial development activity.

Recent construction comprises 90% detached dwellings and 10% medium to high-density housing, sustaining Thornleigh's suburban identity with a concentration of family homes suited for buyers seeking space. The area has approximately 589 people per dwelling approval, demonstrating an established market. Looking ahead, Thornleigh is expected to grow by 50 residents through to 2041, according to the latest AreaSearch quarterly estimate. With current construction levels, housing supply should adequately meet demand, creating favourable conditions for buyers while potentially enabling growth that exceeds current forecasts.

Thornleigh has very high levels of nearby infrastructure activity, ranking in the top 20% nationally

Changes to local infrastructure significantly influence an area's performance. AreaSearch has identified ten projects that could impact this region. Notable projects include Thornleigh Quarter, Thornleigh Marketplace Redevelopment, 15-19 Station Street Mixed-Use Development Thornleigh, and The Sanctuary Thornleigh. Below is a list of those most 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.

AreaSearch analysis reveals Thornleigh recording weaker employment conditions than most comparable areas nationwide

Thornleigh has an educated workforce with significant representation in the technology sector. The unemployment rate was 6.2% as of September 2025. This is 2.0% higher than Greater Sydney's rate of 4.2%.

Workforce participation in Thornleigh is similar to Greater Sydney's 70.0%. According to Census responses, 55.3% of residents work from home, potentially influenced by Covid-19 lockdowns. Key employment industries include health care & social assistance, professional & technical services, and education & training. Education & training has a particularly high share of employment in Thornleigh, at 1.5 times the regional level.

However, transport, postal & warehousing has limited presence, with only 2.6% employment compared to the regional average of 5.3%. The area appears to offer limited local employment opportunities based on Census data comparing working population and resident population. Over a 12-month period ending in September 2025, Thornleigh's labour force increased by 0.9%, while employment declined by 0.1%, leading to an unemployment rate rise of 1.0 percentage points. In comparison, Greater Sydney saw employment growth of 2.1% and a labour force expansion of 2.4%, with a smaller unemployment rate increase of 0.2 percentage points. 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 Thornleigh's employment mix suggests local employment should increase by 7.3% over five years and 14.7% over ten years, though these are simple extrapolations for illustrative purposes and do not account for localized population projections.

Income metrics indicate excellent economic conditions, with the area achieving higher performance than 75% of national locations assessed by AreaSearch

AreaSearch's latest postcode level ATO data for financial year 2023 shows income in Thornleigh is exceptionally high nationally. The median income is $63,859 and the average is $96,146. This contrasts with Greater Sydney's figures of a median income of $60,817 and an average of $83,003. Based on Wage Price Index growth of 8.86% since financial year 2023, current estimates would be approximately $69,517 (median) and $104,665 (average) as of September 2025. Census data reveals household, family and personal incomes all rank highly in Thornleigh, between the 81st and 93rd percentiles nationally. Income distribution shows that 29.5% of locals (2,752 people) earn over $4000 weekly. This differs from the region where the $1,500 - $2,999 category predominates at 30.9%. The area demonstrates considerable affluence with 45.1% earning over $3,000 per week. High housing costs consume 15.4% of income, but strong earnings place disposable income at the 93rd percentile. The area's SEIFA income ranking places it in the 9th decile.

Thornleigh is characterized by a predominantly suburban housing profile, with above-average rates of outright home ownership

Thornleigh's dwelling structure, as per the latest Census, consisted of 76.5% houses and 23.5% other dwellings (semi-detached, apartments, 'other' dwellings), compared to Sydney metro's 55.9% houses and 44.1% other dwellings. Home ownership in Thornleigh stood at 32.1%, with mortgaged dwellings at 44.3% and rented ones at 23.7%. The median monthly mortgage repayment was $2,800, exceeding Sydney metro's average of $2,427. Median weekly rent in Thornleigh was $530, higher than Sydney metro's $470. Nationally, Thornleigh's mortgage repayments were significantly higher than the Australian average of $1,863, and rents were substantially above the national figure of $375.

Thornleigh features high concentrations of family households, with a higher-than-average median household size

Family households account for 81.8% of all households, including 46.8% couples with children, 22.4% couples without children, and 11.4% single parent families. Non-family households make up the remaining 18.2%, with lone person households at 16.2% and group households comprising 2.1%. The median household size is 2.9 people, which is larger than the Greater Sydney average of 2.7.

Thornleigh demonstrates exceptional educational outcomes, ranking among the top 5% of areas nationally based on AreaSearch's comprehensive analysis of qualification and performance metrics

Thornleigh's educational attainment is notably higher than national averages. Among residents aged 15+, 48.7% have university qualifications, compared to Australia's 30.4% and NSW's 32.2%. Bachelor degrees are the most prevalent (30.0%), followed by postgraduate qualifications (15.1%) and graduate diplomas (3.6%). Vocational pathways account for 23.7%, with advanced diplomas at 11.0% and certificates at 12.7%.

Educational participation is high, with 32.4% currently enrolled in formal education: 11.3% in primary, 9.1% in secondary, and 6.3% in tertiary education.

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

Thornleigh has 99 active public transport stops offering a mix of train and bus services. These stops are served by 47 different routes, facilitating 3,827 weekly passenger trips in total. Residents enjoy excellent transport accessibility, with an average distance of 133 meters to the nearest stop. Primarily residential, Thornleigh sees most residents commuting outward. Cars remain the primary mode of transport at 78%, while trains account for 13%. Vehicle ownership stands at 1.4 per dwelling, above the regional average.

According to the 2021 Census, 55.3% of residents work from home, which may reflect COVID-19 conditions. On average, there are 546 trips daily across all routes, equating to approximately 38 weekly trips per individual stop.

Thornleigh's residents are extremely healthy with very low prevalence of common health conditions across all age groups

Analysis of health metrics shows strong performance throughout Thornleigh. AreaSearch's assessment indicates very low prevalence of common health conditions across all age groups. The rate of private health cover is exceptionally high at approximately 65% of the total population (6,048 people), compared to 59.9% across Greater Sydney and a national average of 55.7%.

The most common medical conditions in the area are asthma and mental health issues, impacting 7.3 and 7.2% of residents respectively. Seventy-two point nine percent of residents declare themselves completely clear of medical ailments, compared to 74.6% across Greater Sydney. The under-65 population demonstrates better than average health outcomes. The area has 15.9% of residents aged 65 and over (1,483 people). Health outcomes among seniors are particularly strong, with national rankings even higher than the general population.

Thornleigh 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

Thornleigh has a high level of cultural diversity, with 37.1% of its population born overseas and 32.6% speaking a language other than English at home. Christianity is the predominant religion in Thornleigh, making up 51.0% of the population. Hinduism is overrepresented compared to Greater Sydney, comprising 4.5% of Thornleigh's population versus 5.2%.

The top three represented ancestry groups are English (21.7%), Australian (20.6%), and Other (11.1%). Korean (2.3%) and Lebanese (2.6%) are notably overrepresented compared to regional averages, while Russian is slightly overrepresented at 0.5% versus 0.4%.

Thornleigh's population is slightly older than the national pattern

Thornleigh has a median age of 40, which is slightly higher than Greater Sydney's figure of 37 years and Australia's median age of 38 years. The 45-54 age cohort is notably over-represented in Thornleigh at 15.9%, compared to the Greater Sydney average. Conversely, the 25-34 age group is under-represented at 8.5%. Between 2021 and present, the percentage of the population aged 15-24 has increased from 12.2% to 14.3%, while the 25-34 age group has declined from 9.4% to 8.5%. By 2041, demographic modeling suggests significant changes in Thornleigh's age profile. The 75-84 age cohort is projected to expand by 169 people (31%), growing from 541 to 711 individuals. Notably, the combined age groups of 65 and above will account for 98% of total population growth, reflecting Thornleigh's aging demographic profile. Meanwhile, the 45-54 and 25-34 age cohorts are expected to experience population declines.