Photo: VVVCFFrance · CC BY-SA 4.0Seclin sits above 88% of compared French towns for households in social housing (26%)
The figure for households headed by a manager or professional is 16% in Seclin and 9.4% in the typical compared French town. The share of second homes stands at 0.6%. With a median age of 39.6, Seclin is younger than just over four fifths of compared French towns. The town counted 13,261 residents and 5,750 households at the 2023 Census.
Throughout this page, the Nord 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.
A +6% change since 2012: Seclin grew faster than 56% 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
The change was −1% from 2012 to 2017 and +7% from 2017 to 2023. The median compared French town changed +5% over the same years, the median Nord town ±0%.
A lower share of residents aged 65 and over than 68% of compared French towns, at 19%
Shares of residents by age at the 2023 census.
Age groups · share of residents
Median age of the 3,798 compared French towns
■ Seclin 39.6. The median compared French town: 44.
Residents aged 15 to 24: 12% here and 11% in the typical compared French town. Elsewhere, 22% of residents are 65 or over in the typical compared French town.
Women and men · all residents
52% women, 48% men
About 91 men for every 100 women. Median share of women: Nord 51.9%, France 51.8%.
Seclin sits above 58% of compared French towns for couples with children (27%)
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 Nord median and the France median
Living alone · share
Each household has 2.2 people on average. The comparison figure for couples with children is 25% in the typical compared French town. Higher than in nearly two thirds of compared French towns: 11% of households are single parents. On top of that, just over a third of households are one person living alone in the typical compared French town, against 36% in Seclin.
Above 77% of compared French towns: 17% of households have no car
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
19% of households have been in place 30 years or more; 8.6% moved in within the last two years. In the typical compared French town, the share of households without a car is 11%. At 37%, the share of flats is higher than in three fifths of compared French towns. Where 6.7% of homes stand empty in the typical compared French town, Seclin has 5.2%.
The median resident lives on €24,790 a year per consumption unit
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.
Living standards centre on €24,790 a year per consumption unit: lower than in 63% of compared French towns. Below the poverty threshold: 17.0% of the population.
A smaller share of households headed by a retired person than 69% of compared French towns: 29%
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
In Seclin, 13% of households are headed by a manual worker. 16% of the town’s households are headed by a manager or professional, against 9.4% in the median compared French town; 29% by a retired person (32%).
Each household is counted once, by the occupation of its reference person (usually the oldest working adult).
A lower share of immigrants than 59% of compared French towns, at 5.4%
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.
4% of residents are foreign nationals. Typically, 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.
Seclin sits below 79% of compared French towns for married residents (38%)
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 Seclin, 28% of residents 15 and over are single, beside 25% in the typical compared French town. The benchmark for married residents in the typical compared French town: 43%.
Seclin ranks above 70% of compared French towns on adults with no qualification: 23%
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
The share of graduates of higher education is 34%, against 30% in the typical compared French town. The comparison figure for adults with no qualification is 19% in the typical compared French town.
41 French towns of 12,937 to 13,606 people: this is the 7th 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.
Ages run from 32.3 in Val-de-Reuil to 61.8 in Saint-Hilaire-de-Riez.
5 in 6 nearby towns have a higher median age than Seclin
The nearest towns of 2,500 or more, colored by median age. Source: INSEE, census 2023.
| Town | Median age | 65+ | Second homes | Immigrants |
|---|---|---|---|---|
| Seclin | 39.6 | 19% | 0.6% | 5.4% |
| Gondecourt 4,148 · 2.1 mi | 43 | 20% | 0.8% | 2.1% |
| Templemars 3,669 · 2.1 mi | 42.8 | 21% | 0.5% | 2.9% |
| Phalempin 4,847 · 2.3 mi | 44.7 | 23% | 0.6% | 2.7% |
| Houplin-Ancoisne 3,326 · 2.4 mi | 43.4 | 22% | 1.2% | 3.1% |
| Avelin 2,561 · 2.5 mi | 45.8 | 21% | 0.8% | 2.8% |
| Wattignies 15,525 · 2.8 mi | 37.4 | 19% | 1% | 12% |
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 Seclin
What is the population of Seclin?
13,261 at INSEE’s 2023 census, 6% more than in 2012 (12,479).
How old are Seclin’s residents?
The median age is 39.6, younger than 81% of compared French towns. 23% are under 18 and 19% 65 or older.
How many second homes are there in Seclin?
37, with occasional dwellings: 0.6% of all homes, against 2.1% for the median compared French town.
How many immigrants live in Seclin?
INSEE counts 720 immigrants (born abroad, not French at birth), 5.4% of residents, and 530 foreign nationals (4%). The medians of compared French towns are 6.5% and 4.3%.
What is the median income in Seclin?
€24,790 a year per consumption unit in 2023 (median of compared French towns €25,970); 17.0% 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 9, 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.