A larger share of couples with children than 96% of compared French towns: 37%
Households without a car make up 3.7%, against 11% in the typical compared French town. Sergy counted 2,288 residents and 920 households at the 2023 Census. Locally, 22% of households are headed by a retired person. Lower than in 93% of compared French towns: 14% of residents are 65 or over.
Throughout this page, the Ain median and the France median are the median of compared communes (those with an overall grade), each figure its own median. Source: INSEE, census 2023.
What stands out about the people of Sergy
Immigrants
INSEE counts 800 immigrants in Sergy (people born abroad who weren’t French at birth, whatever their nationality now): 35% of residents, against 8.5% for the median compared commune in Ain. 29% are foreign nationals. Immigrants and foreign nationals ↓
A town of families
37% of households are couples with children and 7.4% single parents with children; 23% of residents are under 15. Households ↓
Many graduates
49% of residents 15 and over who have left education hold a diploma above the bac, 27% a master’s or more (bac+5). Qualifications ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
A +12% change since 2012: Sergy grew faster than 76% of compared French towns
Residents at INSEE’s last three censuses, each recast in the 2026 commune boundaries. France has no yearly estimate by commune between censuses.
2012 to 2023
2017 to 2023
Between 2012 and 2017 the population moved +2%, then +10% to 2023. Over those years, the median Ain town changed +13% and the median compared French town +5%.
Younger than 79% of compared French towns: half of Sergy is under 40
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Sergy 40. The median compared French town: 44.
Where just over one in ten residents are 15 to 24 in the typical compared French town, Sergy has 9.4%.
Women and men · all residents
50% women, 50% men
About an even split. Median share of women: Ain 51.0%, France 51.8%.
Fewer one-person households than 92% of compared French towns: 26%
A household is everyone who shares a main home (résidence principale). Household types come from INSEE’s fuller sample of a quarter of census forms.
Against the Ain median and the France median
Living alone · share
The typical household size is 2.5 people. About one in 14: that is how common single-parent households are in Sergy (7.4%). The share of one-person households in the typical compared French town is 35%.
Sergy: 6.1% of homes are second homes, above 81% of compared French towns
Every home the census counted: main residences, second homes and occasional dwellings (INSEE counts them together), and empty homes. Owning and renting are on Cost of living.
All homes · share of homes
Type of home
Cars per household · share of households
Where just over one in ten households rent social housing (HLM) in the typical compared French town, Sergy has 9%. Lower than in just over three fifths of compared French towns: 5.9% of homes stand empty. On average, 2.1% of homes are second homes in the typical compared French town. Put another way, about one in three: 32% of homes are flats.
Half above, half below €47,140 a year in standard of living
The standard of living (niveau de vie) is a household’s disposable income after taxes and benefits, divided by its consumption units (UC) to allow for its size and make-up: 1 for the first adult, 0.5 for each other person 14 or older, 0.3 for each child under 14.
Medians of compared communes. Source: INSEE, Filosofi 2023.
At €47,140 a year per consumption unit, the median standard of living here is higher than in 99% of compared French towns. As for poverty, 15.0% of residents are below the line.
A higher share of households headed by a manager or professional than 94% of compared French towns, at 25%
Households by the socio-professional group (PCS) of their reference person, INSEE’s own categories. Jobs and commuting are on the Work & commute page.
Households by reference person’s group · share of households
The share of households headed by a manual worker trails 79% of compared French towns: 9.6%. On average, 9.4% of households are headed by a manager or professional in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
Sergy ranks above 99% of compared French towns on immigrants: 35%
INSEE publishes two measures, which overlap but aren’t the same. Neither is the UK’s “born abroad”.
Share of residents · census 2023
Immigrant (immigré)
Born abroad, not French at birth. Someone stays an immigrant after becoming French. A French citizen born abroad (for example in Algeria before 1962) is not one.
Foreign national (étranger)
Not a French citizen today, wherever born. A child born in France to foreign parents can be a foreign national without being an immigrant.
The figure for foreign nationals is 29% in Sergy and 4.3% in the typical compared French town. The median compared commune in Ain has 8.5%; immigrants here make up a share higher than in 99% of compared French towns. The usual figure: 6.5% of residents are immigrants in the typical compared French town.
INSEE publishes no country of birth or ethnicity by commune in these tables, and the census doesn’t ask about religion.
Sergy ranks above 99% of compared French towns on married residents: 55%
Residents 15 and over by how they live: the census asks both the legal status and whether people live as a couple.
Residents 15 and over · share
In the typical compared French town, the share of single residents is 25%; Sergy has 21%. For married residents, the comparison in the typical compared French town is 43%.
Adults with no qualification: 10%, a lower share than 95% of compared French towns
Highest diploma of residents 15 and over who have left education, in French terms: the levels don’t map one-to-one to UK or U.S. ones.
Highest diploma · 15 and over, out of education
In the typical compared French town, the share of graduates of higher education is 30%; Sergy has 49%. The wider picture: nearly a fifth of adults out of school have no qualification in the typical compared French town.
Ranked by age, 3rd youngest of 41 French towns this size
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
Villejust is the youngest (37.2); Prayssac the oldest (62.3).
No nearby town is as old as Sergy
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Sergy | 40 | 14% | 6.1% | 35% |
| Saint-Genis-Pouilly 14,432 · 1.4 mi | 33.9 | 9% | 6.2% | 41% |
| Thoiry 6,569 · 1.5 mi | 39 | 13% | 6.1% | 34% |
| Prévessin-Moëns 9,153 · 3.8 mi | 36.5 | 10% | 11% | 37% |
| Ségny 2,941 · 4.6 mi | 34.8 | 11% | 4.7% | 30% |
| Ornex 5,082 · 4.8 mi | 37.9 | 12% | 4.8% | 38% |
| Ferney-Voltaire 12,094 · 5.3 mi | 36.7 | 12% | 17% | 46% |
Health, work, housing and schools
What this data can and can’t tell you
- Census 2023. INSEE’s census is a rolling survey: a fifth of small communes each year, 8% of homes in large ones each year. “2023” pools the surveys of 2021 to 2025, so the figures describe the town around 2023, not on one day.
- Medians of compared communes. The comparisons are the median of the département’s compared communes and of France’s (those with an overall grade), each figure its own median: not the total for the département or for France, which large cities pull towards their own figures.
- Immigrants and foreign nationals. INSEE’s two measures: an immigrant was born abroad without French nationality; a foreign national isn’t French today. Neither is a count of people born abroad, which INSEE doesn’t publish by commune.
- Second homes. Homes used for holidays or weekends, with occasional dwellings (kept for work, for example), which INSEE counts together. Their owners are counted where they live, not here.
- Standard of living. INSEE’s Filosofi: disposable income per consumption unit, from tax and benefit files, 2023. The poverty rate is the share of residents below 60% of France’s median. Not published for the smallest communes.
- What France doesn’t ask. The French census asks nothing about ethnicity, religion, language or health, so this page has no such section.
Questions about who lives in Sergy
What is the population of Sergy?
2,288 at INSEE’s 2023 census, 12% more than in 2012 (2,035).
How old are Sergy’s residents?
The median age is 40, younger than 79% of compared French towns. 28% are under 18 and 14% 65 or older.
How many second homes are there in Sergy?
64, with occasional dwellings: 6.1% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Sergy?
INSEE counts 790 immigrants (born abroad, not French at birth), 35% of residents, and 670 foreign nationals (29%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Sergy?
€47,140 a year per consumption unit in 2023 (median of compared French towns €25,970); 15.0% of residents live below the poverty line. Source: INSEE, Filosofi.
Sources: INSEE, census 2023 (population, ages, households, homes, marital status, diplomas, immigrants, foreign nationals, employment), 2026 geography · INSEE, Filosofi 2023 (standard of living, poverty) · IGN Admin Express (boundaries) · Medians and percentiles: TownRatings, over compared French towns, updated November 4, 2026. Under the Licence Ouverte / Open Licence 2.0 (Etalab).
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.