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HOLY TRINITY NATIONAL SCHOOL

Roll number: 20190T Glencairn, Leopardstown, Dublin 18

School details

Address
Glencairn, Leopardstown, Dublin 18 (D18YV91)
Email
[email protected]
Phone
012063664
Principal
James Tobin
Ethos
Catholic
DEIS
N
Irish classification
No subjects through Irish
Gaeltacht
N
Island
N
Local authority
Dun Laoghaire Rathdown
School patron
Archbishop of Dublin
School type
Ordinary
School level
All-Through School
Planning area
Ballinteer_Stepaside_DLR

Class size history

Mainstream class group data is shown separately from standard/year-group enrolment data. The source does not identify which standard/year group each class group belongs to.

Average class size
24.42
2025/26
Mainstream classes
24
2025/26
Largest class group
26
2025/26
Classes with 30+ pupils
0
2025/26

Class group metrics trend

Class group metrics by year

Year Mainstream class pupils Mainstream classes Average class size Largest class Classes 30+
2006/07 46 2 23.00 26 0
2007/08 75 3 25.00 31 1
2008/09 103 4 25.75 31 1
2009/10 156 6 26.00 31 2
2010/11 213 8 26.62 37 2
2011/12 267 10 26.70 32 4
2012/13 295 11 26.82 32 3
2013/14 350 13 26.92 33 2
2014/15 375 14 26.79 33 2
2015/16 426 16 26.62 30 1
2016/17 475 18 26.39 31 2
2017/18 516 19 27.16 30 4
2019/20 578 22 26.27 30 3
2020/21 604 23 26.26 31 3
2021/22 601 23 26.13 30 3
2022/23 610 24 25.42 29 0
2023/24 601 24 25.04 28 0
2024/25 596 24 24.83 27 0
2025/26 586 24 24.42 26 0

Data highlights

Key numbers to spot outliers or notable changes.

Summary statistics (class-level data)

Min / max / mean enrolment per class across the available final by-standard years.

Class Min Max Mean Years
Junior Infants 73 82 76.2 6
Senior Infants 68 82 74.8 6
1st Class 69 77 73.3 6
2nd Class 73 82 77.0 6
3rd Class 71 77 74.3 6
4th Class 74 91 77.8 6
5th Class 52 90 74.0 6
6th Class 50 86 72.2 6
Total 20 610 382.1 21

Total enrolment over time

Total and gender trends use historical records where available. Class-level data starts in 2020/21.

Enrolment by gender over time

Enrolment by class over time

Cohort progression

Track how each cohort (pupils who were in the same class in the same year) progresses through the school. Each step shows the count; the number between steps is the net change (pupils gained minus pupils lost).

Cohort 2020/21
JI 2020/21 82
0
SI 2021/22 82
-8
1st 2022/23 74
+2
2nd 2023/24 76
+1
3rd 2024/25 77
-2
4th 2025/26 75
Cohort 2021/22
JI 2021/22 74
+1
SI 2022/23 75
-4
1st 2023/24 71
+3
2nd 2024/25 74
-1
3rd 2025/26 73
Cohort 2022/23
JI 2022/23 77
+2
SI 2023/24 79
-2
1st 2024/25 77
-1
2nd 2025/26 76
Cohort 2023/24
JI 2023/24 76
-6
SI 2024/25 70
-1
1st 2025/26 69
Cohort 2024/25
JI 2024/25 73
-5
SI 2025/26 68
Cohort 2025/26
JI 2025/26 75

Raw data by year

Year Female Male JI SI 1st 2nd 3rd 4th 5th 6th Total
2005/06 9 11 20
2006/07 23 23 46
2007/08 36 39 75
2008/09 42 61 103
2009/10 73 83 156
2010/11 97 116 213
2011/12 121 146 267
2012/13 127 168 295
2013/14 154 196 350
2014/15 158 217 375
2015/16 179 247 426
2016/17 204 271 475
2017/18 214 302 516
2018/19 220 311 531
2019/20 250 328 578
2020/21 268 336 82 75 77 81 71 91 52 75 604
2021/22 270 331 74 82 72 82 76 75 90 50 601
2022/23 290 320 77 75 74 73 77 77 71 86 610
2023/24 274 327 76 79 71 76 72 74 82 71 601
2024/25 274 322 73 70 77 74 77 75 76 74 596
2025/26 271 315 75 68 69 76 73 75 73 77 586