Photo: Jaggery · CC BY-SA 2.0Treorchy ranks above 99% of UK towns on households in terraced houses: 78%
Set against 24% across Wales’s towns, 8% of households live in a detached house in Treorchy. At the 2021 Census Treorchy was home to 7,645 people in 3,397 households. 97% of residents describe themselves as White British. Fewer married adults and civil partners than in 87% of UK towns: 41%.
What the Census says about Treorchy’s people
More with no religion than most
58% of residents answered “no religion” in 2021 and 35% Christian, against 47% and 43% across Wales’s towns. Ethnicity & religion ↓
Fewer people than in 2011
ONS mid-year estimates put Treorchy at 7,700 in 2011 and 7,600 in 2024, down 1%, against 4% for Wales: slower growth than in 88% of UK towns. Since 2011 ↓
Written from the data on this page: ONS Census 2021 (output areas summed to the 2022 built-up area) and ONS mid-year population estimates.
Treorchy changed by −1% from 2011 to 2024, slower than 88% of UK towns
ONS mid-year estimates, each year indexed to mid-2011 = 100. Treorchy’s figure is the small areas (2021 LSOAs) that make up the town.
People, mid-2011 = 100
Change by age, 2011 to 2024
About 7,700 people in 2011; 7,600 in 2024.
Change by age ran from +4% for the 30 to 44 to −8% for the 0 to 15.
Treorchy ranks above 92% of UK towns on residents aged 15 to 24: 12%
Share of residents in each five-year age band, Census 2021.
No age band is larger than 55–59: 8% of residents. Half of Treorchy’s residents are under 44.2, younger than in 52% of UK towns. In Porthcawl, the oldest of Mid Glamorgan’s towns by this measure, it is 33%.
Median age of UK towns of 2,500+
■ Treorchy, 44.2. The typical town is 44.4.
Broad ages · share of residents
Women and men · all residents
52% women, 48% men
About 94 men for every 100 women. Across Wales, 51% of residents are women.
In Treorchy, 5.6% of adults are full-time students, more than in 77% of UK towns
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%.
Across Wales’s towns, 29% of adults are in managerial and professional jobs and 27% in routine work; in Treorchy, 25% and 31%. Against that, 8% of adults are full-time students across Wales’s towns. Residents who moved in within the year: 7.6% of the total.
The Census was taken on 21 March 2021, in term time, so students were counted at their term addresses.
Smaller households than 65% of UK towns: 2.2 people 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.
One-person households make up 32%, close to the figure across Wales’s towns. On shared households of unrelated adults, Treorchy sits lower than just over two thirds of UK towns: 2%. Locally, 26% of households have dependent children.
Above 85% of UK towns: 24% of households have no car or van
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
Against a figure of 14% across Wales’s towns, the share of households in flats in Treorchy comes in at 5.1%. Across Wales’s towns, households without a car or van come to 21%.
Only 2.2% of residents were born outside the UK in Treorchy
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%
When those born abroad arrived
Main language · residents aged 3 and over
Among residents born abroad, the largest groups were born in the Middle East and Asia (0.9%) and in EU countries (0.8%). At 99%, the share of residents whose main language is English is higher than in 92% of UK towns. The benchmark for residents born outside the UK across Wales’s towns: 7.4%. 8.4% of the town’s residents born abroad came in 2017 or later, set against 23% across Wales’s towns.
Welsh is spoken by 15% of Treorchy’s residents
Welsh language skills, residents aged 3 and over, Census 2021.
Welsh language skills · residents aged 3 and over
The 2021 Census found 1,114 Welsh speakers aged 3 and over, 15% of that age group, against 16% across Welsh towns: more than in 66% of them. Top of Mid Glamorgan: Pontyclun, at 20%.
58% of residents said they have no religion, a share 99% of UK towns don’t reach
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 Treorchy · Mid Glamorgan’s towns 95% · Wales’s towns 90%.
Religion · all residents
Of the other groups, the largest are Chinese (1.5%), Other White (0.8%) and Mixed or multiple (0.7%). Fewer residents who describe themselves as Christian than in 97% of UK towns: 35%. For residents with no religion, the comparison across Wales’s towns is 47%.
In Treorchy, 39% of adults have never married or formed a civil partnership, more than in 85% of UK towns
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
Compared with 10% across Wales’s towns, just over one in ten residents give unpaid care here. For comparison, 38% of adults have never married or formed a civil partnership across Wales’s towns.
Degree level: the highest qualification of 26% of adults
Highest qualification, residents 16 and over, Census 2021.
Highest qualification · residents 16 and over
26% of Treorchy’s adults have a degree-level qualification, against 31% across Wales’s towns; 24% have none (20%).
Ranked by age, 225th youngest of 538 UK towns this size
Median age, Census 2021. Hover a dot for its students and residents born abroad; click for its page.
Red Lodge is the youngest (30.9); Barton on Sea the oldest (65.3). Nearest to Treorchy in age: Shaftesbury (44.2), St Blazey (44.2), Crook (44.3) and Market Weighton (44.3).
Treorchy is younger than 1 of its 7 nearest neighbours
Nearby built-up areas coloured by median age, Census 2021. Tap a town for its page.
| Town | People | Away | Median age | 65+ | Homes with children |
|---|---|---|---|---|---|
| Treorchy | 7,645 | — | 44.2 | 22% | 26% |
| Maerdy | 2,843 | 1.5 mi | 41.7 | 21% | 27% |
| Treherbert | 5,427 | 1.6 mi | 43 | 22% | 25% |
| Rhondda | 13,271 | 1.9 mi | 42.3 | 20% | 27% |
| Ferndale | 4,301 | 2.7 mi | 45.4 | 24% | 26% |
| Nant-y-moel | 2,378 | 3 mi | 41.3 | 18% | 28% |
| Tylorstown and Pontygwaith | 3,551 | 3.5 mi | 39.6 | 17% | 27% |
| Tonypandy | 17,209 | 4 mi | 40.3 | 19% | 30% |
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 Treorchy’s figures, so households in open countryside are left out. The population trend compares with the whole county and nation.
- Estimates since 2021 are modelled. The ONS builds mid-year estimates from the Census, births, deaths and migration records. Treorchy’s trend uses the small areas (2021 LSOAs) with most of their people inside it: 7,645 people in 2021, against 7,645 in the built-up area.
- 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 Treorchy’s residents
What is the population of Treorchy?
The 2021 Census counted 7,645 people in Treorchy’s built-up area. The ONS estimates the same small areas held 7,600 people in mid-2024, about as many as in 2011.
What is the average age in Treorchy?
The median age was 44.2 at the 2021 Census, younger than 52% of UK towns. 12% of residents were 15 to 24 and 22% were 65 or over.
How diverse is Treorchy?
97% of residents described themselves as White British in 2021, against 90% across Wales’s towns and 95% across Mid Glamorgan’s towns. 2.2% were born outside the UK.
What religion are people in Treorchy?
58% said they had no religion and 35% that they were Christian at the 2021 Census; 0.1% were Muslim and 5.9% didn’t answer.
Is Treorchy good for families?
26% of households had dependent children in 2021, against 27% across Wales’s towns. Schools are on Treorchy’s schools page.
How many people speak Welsh in Treorchy?
1,114 residents aged 3 and over, 15%, 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) · ONS mid-year population estimates for 2021 LSOAs, mid-2011 to mid-2024. 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.