Bailly sits above 99% of compared French towns for households headed by a manager or professional (37%)
Couples with children: 31% here and 25% in the typical compared French town. Census day 2023: 3,731 residents and 1,610 households in Bailly. 62% of homes are flats. At 7.4%, the share of households in social housing is lower than in 74% of compared French towns.
Throughout this page, the Yvelines 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 Bailly
Many graduates
70% of residents 15 and over who have left education hold a diploma above the bac, 38% a master’s or more (bac+5). Qualifications ↓
Fewer residents than in 2012
Bailly had 3,894 residents at the 2012 census and 3,731 in 2023, down 4%: slower growth than in 85% of compared French towns. Population ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
Since 2012, Bailly has changed by −4%, slower than 85% 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
Over those years, the median Yvelines town changed +7% and the median compared French town +5%.
Older than 69% of compared French towns: half of Bailly is over 47
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Bailly 47. The median compared French town: 44.
Residents aged 15 to 24 make up 11%, close to the figure in the typical compared French town.
Women and men · all residents
53% women, 47% men
About 90 men for every 100 women. Median share of women: Yvelines 51.6%, France 51.8%.
A lower share of one-person households than 62% of compared French towns, at 33%
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 Yvelines median and the France median
Living alone · share
At 9.2%, the share of single-parent households is in line with the figure in the typical compared French town. For comparison, just over a third of households are one person living alone in the typical compared French town. A household here holds 2.3 people on average.
Only 4.6% of homes stand empty in Bailly
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
Car-free households: one in 13, where the median compared French town has 11%. Households without a car are rarer here than in 69% of compared French towns. As a yardstick, 6.7% of homes stand empty in the typical compared French town. About one in 42: that is how common second homes are in Bailly (2.4%).
Half of residents have a standard of living above €43,480 a year
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.
The median standard of living in Bailly is €43,480 a year per consumption unit: higher than in 99% of compared French towns. Below the poverty threshold: 5.0% of the population.
Only 2.1% of households are headed by a manual worker in Bailly
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
Census figures put households headed by a retired person at 33% in Bailly. In the typical compared French town, the share of households headed by a manual worker is 14%.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
A larger share of immigrants than 70% of compared French towns: 10%
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.
In Bailly, 6.8% of residents are foreign nationals, beside 4.3% in the typical compared French town. On average, 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.
51% of residents 15 and over are married, more than in 95% of compared French towns
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
Here nearly a quarter of residents 15 and over are single, where the figure in the typical compared French town is 25%. The benchmark for married residents in the typical compared French town: 43%.
More graduates of higher education than 99% of compared French towns: 70%
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 adults with no qualification is 19%; Bailly has 5.4%. For comparison, 30% of adults out of school hold a higher-education qualification in the typical compared French town.
Among 41 French towns of 3,700 to 3,764 people, the 21st oldest
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
At the ends of the range sit Lourches (35.1), the youngest, and Cabourg (63.9), the oldest.
Around Bailly, 2 of 6 towns have a higher median age
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Bailly | 47 | 24% | 2.4% | 10% |
| Noisy-le-Roi 7,713 · 0.9 mi | 48.4 | 26% | 1.8% | 11% |
| L'Étang-la-Ville 5,157 · 2.1 mi | 45.2 | 19% | 1.6% | 14% |
| Le Chesnay-Rocquencourt 30,689 · 2.3 mi | 47.1 | 26% | 3.4% | 12% |
| Fontenay-le-Fleury 13,680 · 2.4 mi | 38.6 | 17% | 1.9% | 19% |
| Louveciennes 7,990 · 2.5 mi | 43.3 | 22% | 2.8% | 21% |
| Marly-le-Roi 16,756 · 2.5 mi | 44.3 | 21% | 1.7% | 13% |
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 Bailly
What is the population of Bailly?
3,731 at INSEE’s 2023 census, 4% fewer than in 2012 (3,894).
How old are Bailly’s residents?
The median age is 47, older than 69% of compared French towns. 23% are under 18 and 24% 65 or older.
How many second homes are there in Bailly?
41, with occasional dwellings: 2.4% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Bailly?
INSEE counts 370 immigrants (born abroad, not French at birth), 10% of residents, and 260 foreign nationals (6.8%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Bailly?
€43,480 a year per consumption unit in 2023 (median of compared French towns €25,970); 5.0% 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.