Scoil Thomais
Dublin 15 · Roll number 19769W
- Catholic ethos
- Not DEIS
- Ordinary with Special Classes
- Pupils in 2025/26
- 622
- −18 on 2024/25
- Over 10 years
- −10%
- Down 71 from 693 in 2015/16
- 25 classes in 2015/16, 27 now; average class 27.7 → 22.8
- Over 20 years: −13% from 714 in 2005/06
- Girls and boys
- 298 / 324
- 48% girls
Pupils since 1981
Total enrolment each school year
Shaded: the last 10 years, 2015/16 to 2025/26. 1983/84 is left out because its source file is incomplete, and no files exist for 1984/85 to 1992/93. Known data issues
Pupils by class
Published for each class from 2020/21.
This year, 2025/26
622 pupils across 8 classes
Every class, every year
Darker cells have more pupils. A group of pupils moves down one class and right one year.
| 2020/21 | 2021/22 | 2022/23 | 2023/24 | 2024/25 | 2025/26 | Average | |
|---|---|---|---|---|---|---|---|
| Junior Infants | 78 | 95 | 83 | 67 | 84 | 64 | 78.5 |
| Senior Infants | 82 | 78 | 93 | 79 | 65 | 83 | 80.0 |
| 1st Class | 84 | 84 | 75 | 90 | 77 | 69 | 79.8 |
| 2nd Class | 75 | 81 | 85 | 75 | 93 | 75 | 80.7 |
| 3rd Class | 103 | 73 | 85 | 84 | 73 | 90 | 84.7 |
| 4th Class | 80 | 101 | 76 | 81 | 84 | 74 | 82.7 |
| 5th Class | 105 | 77 | 100 | 74 | 85 | 83 | 87.3 |
| 6th Class | 84 | 103 | 78 | 97 | 73 | 84 | 86.5 |
JI and SI are Junior and Senior Infants.
Started Junior Infants in 2024/25
84 in Junior Infants (2024/25), 83 in Senior Infants (2025/26): 1 pupil fewer.
- 84Junior Infants2024/25
- 83Senior Infants2025/26
Started Junior Infants in 2023/24
67 in Junior Infants (2023/24), 69 in 1st Class (2025/26): 2 pupils more.
- 67Junior Infants2023/24
- 65Senior Infants2024/25
- 691st Class2025/26
Started Junior Infants in 2022/23
83 in Junior Infants (2022/23), 75 in 2nd Class (2025/26): 8 pupils fewer.
- 83Junior Infants2022/23
- 79Senior Infants2023/24
- 771st Class2024/25
- 752nd Class2025/26
Started Junior Infants in 2021/22
95 in Junior Infants (2021/22), 90 in 3rd Class (2025/26): 5 pupils fewer.
- 95Junior Infants2021/22
- 93Senior Infants2022/23
- 901st Class2023/24
- 932nd Class2024/25
- 903rd Class2025/26
Started Junior Infants in 2020/21
78 in Junior Infants (2020/21), 74 in 4th Class (2025/26): 4 pupils fewer.
- 78Junior Infants2020/21
- 78Senior Infants2021/22
- 751st Class2022/23
- 752nd Class2023/24
- 733rd Class2024/25
- 744th Class2025/26
In Senior Infants in 2020/21
82 in Senior Infants (2020/21), 83 in 5th Class (2025/26): 1 pupil more.
- 82Senior Infants2020/21
- 841st Class2021/22
- 852nd Class2022/23
- 843rd Class2023/24
- 844th Class2024/25
- 835th Class2025/26
In 1st Class in 2020/21
84 in 1st Class (2020/21), 84 in 6th Class (2025/26): no change.
- 841st Class2020/21
- 812nd Class2021/22
- 853rd Class2022/23
- 814th Class2023/24
- 855th Class2024/25
- 846th Class2025/26
In 2nd Class in 2020/21
75 in 2nd Class (2020/21), 73 in 6th Class (2024/25): 2 pupils fewer.
- 752nd Class2020/21
- 733rd Class2021/22
- 764th Class2022/23
- 745th Class2023/24
- 736th Class2024/25
In 3rd Class in 2020/21
103 in 3rd Class (2020/21), 97 in 6th Class (2023/24): 6 pupils fewer.
- 1033rd Class2020/21
- 1014th Class2021/22
- 1005th Class2022/23
- 976th Class2023/24
In 4th Class in 2020/21
80 in 4th Class (2020/21), 78 in 6th Class (2022/23): 2 pupils fewer.
- 804th Class2020/21
- 775th Class2021/22
- 786th Class2022/23
In 5th Class in 2020/21
105 in 5th Class (2020/21), 103 in 6th Class (2021/22): 2 pupils fewer.
- 1055th Class2020/21
- 1036th Class2021/22
Biggest one-year changes in a class
- +235th Class in 2022/23 (77 to 100)
- −303rd Class in 2021/22 (103 to 73)
Class sizes
Mainstream class groups, 2006/07 to 2025/26.
Why these won't match pupils by class
Mainstream class groups only. The source does not identify which standard/year group each class group belongs to. So these figures won't match the pupils-by-class figures exactly.
In 2025/26. Choose a figure to chart it.
Class sizes over time
Average class size, 2006/07 to 2025/26
Teachers
Who teaches at Scoil Thomais, 2006/07 to 2025/26.
How we count teachers
Class teachers come from the Department of Education's class sizes: one for each mainstream class. Special education and special class teachers are the posts the National Council for Special Education (NCSE) allocates. We add a principal who doesn't teach a class where the Department's rules give the school one. These are posts, not people: part of a post can be a teacher shared with another school. Up to 2015/16 the Department counted every teacher itself. Known data issues
In 2025/26
36.7teaching posts
Our estimate: about 37 teachers.
- Class teachersOne for each of the 27 mainstream classes 27
- PrincipalRuns the school and doesn't teach a class 1
- Deputy principalDoesn't teach a class either, as larger schools and those with five or more special classes have one 1
- Special education teachers167.5 hours of support teaching a week 6.7
- Special class teachersFor an autism class 1
13.32 special needs assistants (SNAs) also work with pupils. 6 pupils are in special classes, which the class sizes leave out.
The NCSE has allocated 6.6 special education teachers, 2 special class teachers and 14.98 SNAs for next year.
Teachers since 2006/07
Teachers each school year, by role
To 2015/16: the Department of Education's count of every teacher. From 2019/20: our estimate, from class sizes and the NCSE's allocations. Dashed boxes: no special education figures were published for those years, so only class teachers and the principal are shown. Known data issues
Sources: Department of Education class sizes and teacher counts; NCSE school allocations and special classes (CC BY 4.0).
Nearby schools
The 6 primary schools closest to Scoil Thomais, measured in a straight line. Pupil numbers are for 2025/26.
| Number on map | School | Distance | Pupils | Since 2015/16 |
|---|---|---|---|---|
| Scoil ThomaisThis school | – | 622 |
−10.2%
|
|
| 1 | St Francis Xavier Senior N S0.6 km · Dublin 15 | 0.6 km | 388 |
+19.0%
|
| 2 | St Francis Xavier J N S0.7 km · Dublin 15 | 0.7 km | 357 |
−12.7%
|
| 3 | Scoil Bride B0.8 km · Dublin 15 · Boys | 0.8 km | 193 |
−43.2%
|
| 4 | Scoil Bride C0.8 km · Dublin 15 · Girls | 0.8 km | 213 |
−31.9%
|
| 5 | Castleknock Educate Together NS1.0 km · Dublin 15 · Multi-denominational | 1.0 km | 374 |
−14.4%
|
| 6 | St Brigids MXD N S1.1 km · Dublin 15 | 1.1 km | 834 |
−12.2%
|
What parents would prefer
In the Department of Education and Youth's Primary School Survey (November–December 2025), parents said whether they would prefer this school to be co-educational or single-sex, to have a denominational or multi-denominational patron, and to teach through Irish or English. These are preferences, not applications or enrolments.
Children at this school
Their parents: 117 of 441 households answered (26%). The true figures are likely within 7.5 points either way.
Patron
Teaching language
Boys and girls
Children not yet at school
Their parents: 71 who intend to enrol a child here answered. The Department gives no margin of error for this group.
Patron
Teaching language
Boys and girls
The bracket shows the margin of error the Department published for this school: 7.5 points either way.
| Parents of | Multi-denominational | Through Irish | Single-sex |
|---|---|---|---|
| This school · children at school | 43% | 22% | 0% |
| This school · children not yet at school | 42% | 24% | 0% |
| Carpenterstown–D15 planning area · children at school | 53% | 17% | 3% |
| Carpenterstown–D15 planning area · children not yet at school | 52% | 22% | 3% |
| Ireland · children at school | 44% | 20% | 5% |
| Ireland · children not yet at school | 47% | 26% | 6% |
Source: Department of Education and Youth, Primary School Survey results, published 23 June 2026. Planning-area and Ireland figures also count parents at schools where too few answered for the school to get its own results. About these figures
About this school
Inspection reports open on gov.ie, under the name the school had when it was inspected. They describe specific areas of the school's work rather than giving an overall grade. Newer schools may not have one yet.
Contact
- Principal
- Lorna Diffley
- Phone
- 018201022
- [email protected]
- Address
- Laurel Lodge, Castleknock, Dublin 15, D15 VW02
School
- Ethos
- Catholic
- Patron
- Archbishop of Dublin
- School type
- Ordinary with Special Classes
- School level
- All Through
- DEIS
- Not DEIS
Language and area
- Irish classification
- No subjects through Irish
- Gaeltacht
- Non-Gaeltacht
- Island
- Not on an island
- Local authority
- Fingal County Council
- Planning area
- Carpenterstown–D15
Each detail is the latest one the Department of Education has recorded for this school. If a detail was left blank in 2025/26, we show it from an earlier year, so some details may be older than the pupil numbers. Known data issues
Data by year
36 school years from 1981/82 to 2025/26. Class figures start in 2020/21.
| Year | Total | Girls | Boys | JI | SI | 1st | 2nd | 3rd | 4th | 5th | 6th |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025/26 | 622 | 298 | 324 | 64 | 83 | 69 | 75 | 90 | 74 | 83 | 84 |
| 2024/25 | 640 | 303 | 337 | 84 | 65 | 77 | 93 | 73 | 84 | 85 | 73 |
| 2023/24 | 653 | 305 | 348 | 67 | 79 | 90 | 75 | 84 | 81 | 74 | 97 |
| 2022/23 | 675 | 313 | 362 | 83 | 93 | 75 | 85 | 85 | 76 | 100 | 78 |
| 2021/22 | 692 | 324 | 368 | 95 | 78 | 84 | 81 | 73 | 101 | 77 | 103 |
| 2020/21 | 691 | 321 | 370 | 78 | 82 | 84 | 75 | 103 | 80 | 105 | 84 |
| 2019/20 | 706 | 333 | 373 | – | – | – | – | – | – | – | – |
| 2018/19 | 708 | 330 | 378 | – | – | – | – | – | – | – | – |
| 2017/18 | 693 | 327 | 366 | – | – | – | – | – | – | – | – |
| 2016/17 | 705 | 330 | 375 | – | – | – | – | – | – | – | – |
| 2015/16 | 693 | 346 | 347 | – | – | – | – | – | – | – | – |
| 2014/15 | 695 | 350 | 345 | – | – | – | – | – | – | – | – |
| 2013/14 | 687 | 339 | 348 | – | – | – | – | – | – | – | – |
| 2012/13 | 681 | 331 | 350 | – | – | – | – | – | – | – | – |
| 2011/12 | 679 | 328 | 351 | – | – | – | – | – | – | – | – |
| 2010/11 | 670 | 331 | 339 | – | – | – | – | – | – | – | – |
| 2009/10 | 666 | 325 | 341 | – | – | – | – | – | – | – | – |
| 2008/09 | 648 | 316 | 332 | – | – | – | – | – | – | – | – |
| 2007/08 | 675 | 323 | 352 | – | – | – | – | – | – | – | – |
| 2006/07 | 678 | 315 | 363 | – | – | – | – | – | – | – | – |
| 2005/06 | 714 | 321 | 393 | – | – | – | – | – | – | – | – |
| 2004/05 | 735 | 322 | 413 | – | – | – | – | – | – | – | – |
| 2003/04 | 777 | 366 | 411 | – | – | – | – | – | – | – | – |
| 2002/03 | 835 | 392 | 443 | – | – | – | – | – | – | – | – |
| 2001/02 | 854 | 407 | 447 | – | – | – | – | – | – | – | – |
| 2000/01 | 886 | 420 | 466 | – | – | – | – | – | – | – | – |
| 1999/00 | 914 | 436 | 478 | – | – | – | – | – | – | – | – |
| 1998/99 | 970 | 461 | 509 | – | – | – | – | – | – | – | – |
| 1997/98 | 962 | 467 | 495 | – | – | – | – | – | – | – | – |
| 1996/97 | 923 | 454 | 469 | – | – | – | – | – | – | – | – |
| 1995/96 | 874 | 427 | 447 | – | – | – | – | – | – | – | – |
| 1994/95 | 859 | 419 | 440 | – | – | – | – | – | – | – | – |
| 1993/94 | 859 | 419 | 440 | – | – | – | – | – | – | – | – |
| 1983/84 | 169 | 81 | 88 | – | – | – | – | – | – | – | – |
| 1982/83 | 134 | 60 | 74 | – | – | – | – | – | – | – | – |
| 1981/82 | 50 | 19 | 31 | – | – | – | – | – | – | – | – |