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, as of November 2025, is estimated at around 9,333 people. This figure reflects an increase of 435 individuals since the 2021 Census, which reported a population of 8,898. The growth is inferred from AreaSearch's estimation of the resident population as 9,176 in June 2024, based on the latest ERP data release by the ABS and an additional 84 validated new addresses since the Census date. This results in a density ratio of 2,411 persons per square kilometer, placing Thornleigh (SA2) in the upper quartile relative to national locations assessed by AreaSearch. The area's 4.9% growth since census is within 2.7 percentage points of the state's growth rate of 7.6%, indicating competitive growth fundamentals. Overseas migration contributed approximately 91.0% of overall population gains during recent periods, driving primary growth for the area.

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, AreaSearch utilises NSW State Government's SA2 level projections, released in 2022 with a base year of 2021. Growth rates by age group from these aggregations are applied to all areas for years 2032 to 2041. Based on aggregated SA2-level projections, the Thornleigh statistical area (Lv2) is expected to increase by 175 persons to 2041, reflecting a gain of 0.2% in total over the 17-year period.

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

AreaSearch analysis of ABS building approval numbers indicates Thornleigh averaged around 29 new dwelling approvals annually over the past five financial years, totalling an estimated 147 homes. As of FY-26, three approvals have been recorded. Over these five years, an average of 1.1 new residents arrived per new home built. However, this figure has increased to 8.4 people per dwelling over the past two financial years, suggesting a rise in demand and tightening supply. Development projects averaged $741,000 in construction value, indicating developers target the premium market segment with higher-end properties.

This year, $10.3 million in commercial approvals have been registered, reflecting balanced commercial development activity. Recent construction comprises 90% detached dwellings and 10% medium to high-density housing, maintaining 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. According to AreaSearch's latest quarterly estimate, Thornleigh is expected to grow by 20 residents through to 2041. 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 strong levels of nearby infrastructure activity, ranking in the top 30% nationally

Changes to local infrastructure significantly influence an area's performance. AreaSearch has identified ten projects likely to impact the area. Notable ones 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 the technology sector prominently represented. Its unemployment rate is 6.2%.

Employment stability in the area over the past year was relative to other regions. As of September 2025, 4815 residents were employed, but the unemployment rate was higher than Greater Sydney's at 6.2% versus 4.2%. Workforce participation was high at 67.0%, compared to Greater Sydney's 60.0%. Leading industries for Thornleigh residents include health care & social assistance, professional & technical services, and education & training.

Education & training has a particularly strong presence, with an employment share 1.5 times the regional level. Conversely, transport, postal & warehousing has limited representation at 2.6% compared to the regional average of 5.3%. Over the past year, Thornleigh's labour force increased by 0.9%, but employment declined slightly by 0.1%, leading to a rise in unemployment rate by 0.9 percentage points. In comparison, Greater Sydney saw employment grow by 2.1% and labour force expand by 2.4%, with a smaller increase in unemployment at 0.2 percentage points. State-wide, as of 25-Nov-25, NSW employment contracted slightly by 0.03%, losing 2260 jobs, with an unemployment rate of 3.9%. Nationally, the unemployment rate was 4.3% during this 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. However, these projections vary significantly between industry sectors. 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, although 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 data for financial year 2023 shows Thornleigh's median income at $63,859 and average income at $96,146. Greater Sydney's median is $60,817 with an average of $83,003. By September 2025, estimated incomes would be approximately $69,517 (median) and $104,665 (average), based on Wage Price Index growth of 8.86%. Thornleigh's household, family, and personal incomes rank between the 81st and 93rd percentiles nationally. Income distribution shows 29.5% (2,753 people) earn over $4000 weekly, differing from the region where 30.9% fall in the $1,500-$2,999 category. Affluence is evident with 45.1% earning over $3,000 weekly. High housing costs consume 15.4% of income, but strong earnings place disposable income at the 93rd percentile, and SEIFA income ranking places Thornleigh in the 9th decile.

Thornleigh is characterized by a predominantly suburban housing profile, with strong 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). Home ownership in Thornleigh stood at 32.1%, with 44.3% of dwellings mortgaged and 23.7% rented. The median monthly mortgage repayment was $2,800, and the median weekly rent was $530. Nationally, Thornleigh's mortgage repayments were significantly higher than the Australian average of $1,863, while rents were substantially above the national figure of $375.

Thornleigh features high concentrations of family households, with a median household size of 2.9 people

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 constitute the remaining 18.2%, with lone person households comprising 16.2% and group households making up 2.1%. The median household size is 2.9 people.

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 high, with 48.7% of residents aged 15+ possessing university qualifications, compared to Australia's 30.4% and NSW's 32.2%. Bachelor degrees are the most common at 30.0%, followed by postgraduate qualifications (15.1%) and graduate diplomas (3.6%). Vocational pathways account for 23.7% of qualifications, with advanced diplomas at 11.0% and certificates at 12.7%. Educational participation is high, with 32.4% currently enrolled in formal education, including 11.3% in primary, 9.1% in secondary, and 6.3% in tertiary education.

Educational participation is notably high, with 32.4% of residents currently enrolled in formal education. This includes 11.3% in primary education, 9.1% in secondary education, and 6.3% pursuing 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 that facilitate 3,827 weekly passenger trips in total. The average distance from residents to the nearest stop is 133 meters, indicating excellent transport accessibility.

On average, there are 546 trips per day across all routes, which translates 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

Thornleigh exhibits robust health metrics with minimal prevalence of common health conditions across all age groups. Private health cover is notably high at approximately 65% of the total population of 6050 individuals, surpassing the national average of 55.7%.

Asthma and mental health issues are the most prevalent medical conditions in the area, affecting 7.3% and 7.2% of residents respectively. Conversely, 72.9% report being completely clear of medical ailments compared to 0% across Greater Sydney. The area has a senior population of 15.3%, comprising 1427 individuals aged 65 and over. Health outcomes among seniors align closely with those of 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.

The top three represented ancestry groups are English (21.7%), Australian (20.6%), and Other (11.1%). Korean (2.3%), Lebanese (2.6%), and Russian (0.5%) ethnic groups are notably overrepresented in Thornleigh compared to the regional average.

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 and Australia's median age of 38. Compared to the Greater Sydney average, Thornleigh has an over-representation of the 45-54 age cohort (16.0%), while the 25-34 age group is under-represented (8.8%). Between 2021 and present, the 15-24 age group has increased from 12.2% to 13.9%, while the 5-14 cohort has decreased from 15.4% to 14.7%. By 2041, demographic modeling suggests significant changes in Thornleigh's age profile. The 85+ age group is projected to grow by 173 people (98%), from 177 to 351. Notably, the combined 65+ age groups will account for 98% of total population growth, reflecting the area's aging demographic trend. Meanwhile, the 45-54 and 15-24 cohorts are expected to experience population declines.