Llancaiach-fawr · Photo: Rose Cottage · Public domainA larger share of households with dependent children than 96% of UK towns: 37%
One-person households: 25% here and 32% across Wales’s towns. The 2021 Census counted 2,022 residents in 826 households. Here, 97% of residents describe themselves as White British. On households in flats, Trelewis sits lower than 71% of UK towns: 7.1%.
What the Census says about Trelewis’s people
A village of families
37% of Trelewis’s 826 households had dependent children in 2021, more than in 96% of UK towns. 21% of residents are under 15. Households ↓
More with no religion than most
62% of residents answered “no religion” in 2021 and 32% Christian, against 47% and 43% across Wales’s towns. Ethnicity & religion ↓
Younger than most towns
Half of Trelewis’s residents are under 37.1 and half over, against 44.4 in the typical UK town. 9.7% are 15 to 24 and 16% are 65 or over. Ages ↓
Written from the data on this page: ONS Census 2021 (output areas summed to the 2022 built-up area).
Younger than 92% of UK towns: half of Trelewis is under 37.1
Share of residents in each five-year age band, Census 2021.
Compared with 21% across Wales’s towns, 16% of residents are 65 or over here. Across Trelewis, one in ten residents are aged 15 to 24.
Broad ages · share of residents
Women and men · all residents
50% women, 50% men
About an even split. Across Wales, 51% of residents are women.
Trelewis ranks below 98% of UK towns on residents who moved in within the year: 5.7%
What adults did at the 2021 Census (the ONS’s NS-SEC classes), and where residents lived a year earlier.
Adults by occupation class · residents 16 and over
Address a year before the Census
Residents who lived somewhere else a year earlier. The bar runs to 25%.
In Trelewis, 5.1% of adults are full-time students, beside 8% across Wales’s towns. The share of residents who moved in within the year across Wales’s towns is 9.1%.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
Bigger households than 82% of UK towns: 2.4 people each on average
Household make-up at the 2021 Census. Each square is 1% of households.
Against Mid Glamorgan’s towns and Wales’s towns
People per household
Wales’s towns.
The census found that 2.3% of households are unrelated adults sharing a home in Trelewis.
Only 21% of households in Trelewis live in a detached house
Accommodation type and cars or vans per household, Census 2021. Owning and renting are on Cost of living.
Type of home
Cars or vans · share of households
29% of households live in a terraced house, about the same as across Wales’s towns. Compared with other places, households without a car or van are common here: 18%, more than in 63% of UK towns. On average, 24% of households live in a detached house across Wales’s towns.
A lower share of residents born outside the UK than 99% of UK towns, at 1.9%
Country of birth, year of arrival and main language, Census 2021.
Born outside the UK, by region · share of all residents; the bar runs to 10%
Main language · residents aged 3 and over
Set against 96% across Wales’s towns, 99% of residents have English as their main language in Trelewis. The two biggest birthplaces abroad are in EU countries (1.1%) and in the Middle East and Asia (0.6%). Typically, 7.4% of residents were born outside the UK across Wales’s towns.
Can speak Welsh: 9.7% of Trelewis’s residents
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
Asked in 2021, 187 residents aged 3 and over, 9.7%, said they can speak Welsh; across Welsh towns, 16%: fewer than in 72% of Welsh towns. Within Mid Glamorgan, Pontyclun has the largest share, 20%.
Residents with no religion make up 62% in Trelewis, more than in 99% of UK towns
How residents described themselves at the 2021 Census. Lines join the lowest and highest of the three figures.
Ethnic groups other than White British · all residents
White British, not charted: 97% of Trelewis · Mid Glamorgan’s towns 95% · Wales’s towns 90%.
Religion · all residents
The share of residents who describe themselves as Christian is 32%, against 43% across Wales’s towns. To put it in context, 47% of residents said they have no religion across Wales’s towns.
A lower share of married adults and civil partners than 72% of UK towns, at 45%
Legal partnership status (residents 16 and over) and unpaid care (residents 5 and over), Census 2021.
Partnership status · residents 16 and over
Unpaid care given · share of residents 5 and over
The figure for adults who have never married is 37% in Trelewis and 38% across Wales’s towns. On the census count, just over one in ten residents give unpaid care. Married adults and civil partners: 43% across Wales’s towns, for comparison.
A degree-level qualification for 27% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
24% of Trelewis’s adults have no qualification (20% across Wales’s towns), and 27% have one at degree level (31%).
A younger town than 6 of the 7 around it: Trelewis
Nearby built-up areas coloured by median age, Census 2021. Tap a town for its page.
Health, work and homes have their own pages
What this data can and can’t tell you
- The Census was taken in a lockdown, in term time. 21 March 2021 fell in term time, and students were asked to give their term-time address, so most were counted where they study. Some may have been living with family that day.
- “Mid Glamorgan’s towns” and “Wales’s towns” mean their built-up areas. Census comparisons pool every built-up area in Mid Glamorgan (or Wales), summed the same way as Trelewis’s figures, so households in open countryside are left out.
- Small counts are blurred. The ONS adds small random changes to Census counts to protect privacy, so the same total differs a little between tables, and the shares of a small town can move by a point or two.
Questions about Trelewis’s residents
What is the population of Trelewis?
The 2021 Census counted 2,022 people in Trelewis’s built-up area.
What is the average age in Trelewis?
The median age was 37.1 at the 2021 Census. 9.7% of residents were 15 to 24 and 16% were 65 or over.
How diverse is Trelewis?
97% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 95% across Mid Glamorgan’s towns. 1.9% were born outside the UK.
What religion are people in Trelewis?
62% said they had no religion and 32% that they were Christian at the 2021 Census; 0.3% were Muslim and 5.5% didn’t answer.
Is Trelewis good for families?
37% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Trelewis’s schools page.
How many people speak Welsh in Trelewis?
187 residents aged 3 and over, 9.7%, said they can speak Welsh at the 2021 Census, against 16% across Welsh towns.
Sources: ONS Census 2021, output areas summed to the ONS 2022 built-up area (TS002, TS003, TS004, TS007A, TS008, TS015, TS017, TS019, TS021, TS029, TS030, TS039, TS044, TS045, TS062, TS067, TS032). All under the Open Government Licence v3.0.
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.