Couples with children: 39%, a higher share than 98% of compared French towns
42% of households are headed by a manager or professional (typical compared French town: 9.4%). Mareil-Marly counted 4,141 residents and 1,570 households at the 2023 Census. Census figures put residents aged 65 and over at 16% locally. Lower than in 85% of compared French towns: 4.2% of homes stand empty.
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 Mareil-Marly
A town of families
39% of households are couples with children and 9.3% single parents with children; 21% of residents are under 15. Households ↓
Many graduates
73% of residents 15 and over who have left education hold a diploma above the bac, 45% a master’s or more (bac+5). Qualifications ↓
Immigrants
INSEE counts 600 immigrants in Mareil-Marly (people born abroad who weren’t French at birth, whatever their nationality now): 15% of residents, against 15% for the median compared commune in Yvelines. 11% are foreign nationals. Immigrants and foreign nationals ↓
Growing fast
Mareil-Marly had 3,519 residents at the 2012 census and 4,141 in 2023, up 18%: faster growth than in 87% of compared French towns. Population ↓
Written from INSEE’s census 2023 on this page, against compared French towns.
A growing town: +18% since 2012, faster than 87% 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 the whole period the median compared French town changed +5%, and the median Yvelines town +7%. The years 2012 to 2017 brought −2%; 2017 to 2023, +20%.
12% of residents are 15 to 24, more than in 74% of compared French towns
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Mareil-Marly 43.2. The median compared French town: 44.
The median age in Mareil-Marly is 43.2, lower than in 56% of compared French towns. By way of comparison, 11% of residents are 15 to 24 in the typical compared French town.
Women and men · all residents
51% women, 49% men
About an even split. Median share of women: Yvelines 51.6%, France 51.8%.
Fewer one-person households than 97% of compared French towns: 23%
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
Single-parent households are about as common here as in the typical compared French town: 9.3%. Typically, 35% of households are one person living alone in the typical compared French town. Households here average 2.6 people each.
A lower share of households in social housing than 84% of compared French towns, at 5.5%
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
Against a figure of 11% in the typical compared French town, the share of households without a car in Mareil-Marly comes in at 6.6%. Census figures put flats at 36% locally. 3.1% of homes are second homes, more than in 63% of compared French towns. In the typical compared French town, 12% of households rent social housing (HLM).
€43,970 a year is the median standard of living here
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.
Half of Mareil-Marly’s residents live in households with a standard of living below €43,970 a year per consumption unit, and half above: higher than in 99% of compared French towns. Living below the poverty line: 4.0% of residents.
Mareil-Marly sits below 99% of compared French towns for households headed by a manual worker (1%)
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
Nearly a third of households are headed by a retired person in the typical compared French town, against 23% in Mareil-Marly. Typically, 14% of households are headed by a manual worker in the typical compared French town.
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
15% of residents are immigrants, more than in 85% of compared French towns
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.
11% of residents are foreign nationals, against 4.3% in the typical compared French town. Immigrants make up 6.5% 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.
A larger share of married residents than 99% of compared French towns: 56%
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
For Mareil-Marly, the census puts single residents at 24%. In the median compared French town 43% are married and 6.1% in a PACS; here it is 56% and 4.9%, and 4% are widowed.
Mareil-Marly sits above 99% of compared French towns for graduates of higher education (73%)
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
Adults with no qualification: 5.7% here and 19% in the typical compared French town. In the typical compared French town, graduates of higher education come to 30%.
41 French towns of 4,113 to 4,170 people: this is the 20th youngest
The 40 compared French towns nearest in population, by median age. Hover for each one’s second homes and immigrants; click for its page.
Chanteloup-en-Brie is the youngest (36.5); Fouras the oldest (62.9).
A younger town than 3 of the 6 around it: Mareil-Marly
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Mareil-Marly | 43.2 | 16% | 3.1% | 15% |
| Marly-le-Roi 16,756 · 0.8 mi | 44.3 | 21% | 1.7% | 13% |
| L'Étang-la-Ville 5,157 · 1 mi | 45.2 | 19% | 1.6% | 14% |
| Saint-Germain-en-Laye 45,931 · 1.1 mi | 41.3 | 18% | 4.2% | 19% |
| Le Pecq 16,059 · 1.4 mi | 42.5 | 19% | 1.1% | 17% |
| Le Port-Marly 5,559 · 1.4 mi | 37.4 | 15% | 3% | 24% |
| Louveciennes 7,990 · 2.2 mi | 43.3 | 22% | 2.8% | 21% |
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 Mareil-Marly
What is the population of Mareil-Marly?
4,141 at INSEE’s 2023 census, 18% more than in 2012 (3,519).
How old are Mareil-Marly’s residents?
The median age is 43.2, younger than 56% of compared French towns. 27% are under 18 and 16% 65 or older.
How many second homes are there in Mareil-Marly?
52, with occasional dwellings: 3.1% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Mareil-Marly?
INSEE counts 620 immigrants (born abroad, not French at birth), 15% of residents, and 480 foreign nationals (11%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Mareil-Marly?
€43,970 a year per consumption unit in 2023 (median of compared French towns €25,970); 4.0% 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.