Semaphore (SA)

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Based on evaluation of ABS demographic updates for the wider region, and new addresses validated by Districts since the Census Semaphore's population is estimated at around 2,814 as of May 2026. This reflects an increase of 65 people (2.4%) since the 2021 Census, which reported a population of 2,749 people. The change is inferred from the resident population of 2,810, estimated by Districts following examination of the latest ERP data release by the ABS (June 2025) and an additional 12 validated new addresses since the Census date. This level of population equates to a density ratio of 2,654 persons per square kilometer, placing it in the upper quartile relative to national locations assessed by Districts. Population growth for the area was primarily driven by overseas migration that contributed approximately 69.0% of overall population gains during recent periods, although all drivers including interstate migration and natural growth were positive factors.

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Semaphore has a well-educated workforce, with essential services sectors well represented, an unemployment rate of just 2.6%, and 6.3% in estimated employment growth over the past year, based on Districts aggregation of statistical area data. As of March 2026, 1,708 residents are in work while the unemployment rate is 1.2% below Greater Adelaide's rate of 3.8%, and workforce participation is fairly standard (69.5% compared to Greater Adelaide's 66.6%). Based on Census responses, a moderate 14.4% of residents were found to work from home, though Covid-19 lockdown impacts should be considered.

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According to Districts' aggregation of the latest postcode level ATO data released for financial year 2023, the suburb of Semaphore had a median income among taxpayers of $56,795 with the average level standing at $67,101. This is in line with the national averages and compares to levels of $54,808 and $66,852 across Greater Adelaide respectively. Based on Wage Price Index growth of 10.17% since financial year 2023, current estimates would be approximately $62,571 (median) and $73,925 (average) as of March 2026. Census 2021 income data shows household, family and personal incomes in Semaphore cluster around the 54th percentile nationally. Looking at income distribution, the $1,500 - 2,999 bracket dominates with 30.9% of residents (869 people), mirroring the broader area where occupy this bracket. After housing, of income remains for other expenses and the area's SEIFA income ranking places it in the th decile.

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Dwelling structure within Semaphore, as evaluated at the latest Census, comprised 65.4% houses and 34.5% other dwellings (semi-detached, apartments, 'other' dwellings), in comparison to Adelaide metro's 75.2% houses and 24.9% other dwellings. Meanwhile, the level of home ownership within Semaphore was well beyond that of Adelaide metro, at 35.9%, with the remainder of dwellings either mortgaged (33.6%) or rented (30.5%). The median monthly mortgage repayment in the area was well above the Adelaide metro average at $1,733, while the median weekly rent figure was recorded at $320, compared to Adelaide metro's $1,562 and $320. Nationally, Semaphore's mortgage repayments are lower than the Australian average of $1,863, while rents are substantially below the national figure of $375.

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Family households dominate at 65.0% of all households, comprising 22.9% couples with children, 30.0% couples without children, and 10.1% single parent families. Non-family households make up the remaining 35.0%, with lone person households at 31.8% and group households comprising 3.4% of the total. The median household size of 2.2 people is smaller than the Greater Adelaide average of 2.5.

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Educational attainment in Semaphore significantly surpasses broader benchmarks, with 33.2% of residents aged 15+ holding university qualifications compared to 22.6% in SA3 area and 25.7% in SA. This substantial educational advantage positions the area strongly for knowledge-based opportunities. Bachelor degrees lead at 20.2%, followed by postgraduate qualifications (8.9%) and graduate diplomas (4.1%). Trade and technical skills feature prominently, with 34.5% of residents aged 15+ holding vocational credentials – advanced diplomas (11.8%) and certificates (22.7%).

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Public transport analysis reveals 14 active transport stops operating within Semaphore comprising a mix of buses. These stops are serviced by 11 individual routes, collectively providing 247 weekly passenger trips. Transport accessibility is rated as excellent, with residents typically located 167 meters from the nearest transport stop. As a primarily residential area, most residents commute outward - car remains the dominant mode at 87%, with 2% cycling. Vehicle ownership averages 1.2 per dwelling, below the regional average. Some 14.4% of residents work from home (2021 Census; may reflect COVID-19 conditions).

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Health indicators suggest below-average outcomes in Semaphore, based on Districts' assessment of mortality rates and chronic condition prevalence with the level of common health conditions among the general population somewhat typical, though higher than the nation's average among older cohorts , and the rate of private health cover just leading that of the average SA2 area at approximately 54% of the total population (~1,506 people).

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Semaphore was found to be roughly in line with the wider region's average in terms of cultural diversity, with 77.0% of its population born in Australia, 88.9% being citizens, and 91.5% speaking English only at home. The main religion in Semaphore was found to be Christianity, which makes up 39.7% of people in Semaphore. However, the most apparent overrepresentation was in Islam, which comprises 1.2% of the population, compared to 3.0% across Greater Adelaide.

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With a median age of 50, Semaphore is materially older than the Greater Adelaide figure of 39 as well as significantly higher than the national norm of 38. The 55 - 64 age group shows strong representation at 20.8% compared to Greater Adelaide, whereas the 25 - 34 cohort is less prevalent at 9.3%. This 55 - 64 concentration is well above the national 11.2%. Post-2021 Census data shows the 75 to 84 age group has grown from 5.0% to 7.0% of the population, while the 65 to 74 cohort increased from 13.3% to 14.7%. Conversely, the 45 to cohort has declined from to . By Semaphore is expected to see notable shifts in its age composition. Leading the demographic shift, the to group will grow by ( people), reaching from . The aging population dynamic is clear, with those + comprising of projected growth. Conversely, population declines are projected for the to and to cohorts.

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Semaphore currently has an estimated 90 children under 5 years old, comprising approximately 83 children aged 0-2 and 54 children aged 3-4. This cohort grew by an estimated 3% since the previous census. though population forecasts indicate future decline, with an anticipated decrease of 3% by 2041 (to approximately 87 children). Meanwhile the 5-12 cohort currently amounts to 211. While growth has been positive birth rates observed in the area have been moderate, with approximately 8.8 births per 1,000 residents recorded over the latest two-year period analysed which ranks the area within the middle tier nationally. This rate has slowed down slightly in recent years however.