Mount Sackville Secondary School
Chapelizod, Dublin
Key facts
- Girls
- Pupils enrolled
- 636 about the same size as the median Irish post-primary school (585 pupils)
- Ethos
- Catholic
- Teaching through Irish
- No subjects taught through Irish
- Roll number
- 60120W the Department of Education reference for this school
School details
Location
About
Mount Sackville Secondary School is an all‑girls, fee‑charging Catholic secondary school situated in Chapelizod, Dublin 20. The school operates under the trusteeship of Le Chéile and follows the Cluny ethos, embedding Gospel values of faith, hope and love into every aspect of school life. A strong pastoral and student‑support system creates a safe, caring environment where pupils feel a sense of belonging and are encouraged to develop morally, spiritually, emotionally, socially and academically. The curriculum is broad and challenging, offering a range of academic subjects, including senior cycle programmes such as Accounting, Agricultural Science, Applied Mathematics, Art, Biology and more, alongside a vibrant co‑curricular programme that includes sports, performing arts, service projects and leadership opportunities. The school places a high priority on academic excellence, with consistently outstanding examination results that enable graduates to progress to a variety of third‑level institutions. Emphasis is placed on holistic development, with initiatives such as the Wellread Award, literacy and numeracy programmes, and a senior‑cycle redevelopment project that enhances learning spaces and resources. The community ethos is reinforced through collaboration between teachers, staff, parents/guardians and students, fostering an environment where young women can thrive, flourish and reach their full potential.
History
Mount Sackville was founded in 1864 by the Sisters of St Joseph of Cluny. The school celebrates over 160 years of Cluny education, preserving the spirit of care and compassion established by its founding sisters while evolving to meet contemporary educational needs.
Applying to Mount Sackville Secondary School
For a September 2027 place, a school's formal admissions process cannot begin before 1 October 2026. The school sets its own opening and closing dates in its annual admission notice.
National term dates 2026/27
View Mount Sackville Secondary School's own calendar (2026/2027 school year)
Irish schools follow a standardised school year, so these nationwide post-primary school dates apply broadly to Mount Sackville Secondary School. The school publishes its own calendar, linked above, and that is the authoritative source for its reopening date and discretionary closure days.
- October Mid-Term Break: Mon 26 Oct – Fri 30 Oct 2026
- Christmas Holidays: Wed 23 Dec 2026 – Tue 5 Jan 2027
- February Mid-Term Break: Mon 15 Feb – Fri 19 Feb 2027 (primary schools: Thu 18 Feb – Fri 19 Feb 2027)
- Easter Holidays: Mon 22 Mar – Sun 4 Apr 2027
Primary schools close for the last two days of the February mid-term week and may use discretionary days to take the full week, so their break can be shorter than post-primary schools'.
Frequently asked questions about Mount Sackville Secondary School
How many pupils attend Mount Sackville Secondary School?
Mount Sackville Secondary School has 636 pupils enrolled. That makes it about the same size as the median Irish post-primary school, which has 585 pupils.
Is Mount Sackville Secondary School a DEIS school?
No. Mount Sackville Secondary School is not part of DEIS, the Department of Education programme of additional supports for schools serving communities at risk of educational disadvantage. Not holding DEIS status says nothing about how good a school is, only about the profile of the community it serves.
What is the ethos of Mount Sackville Secondary School?
Mount Sackville Secondary School has a Catholic ethos. It is a girls' post-primary school.