St Mary's School
Updated Oct 2026 · ACARA 2025Williamstown, Victoria 3016 · Hobsons Bay LGA
#507 of 1,290 primary schools in VIC
#1398 of 4,908 nationally
About St Mary's School
St Mary's School is a catholic primary school located in Williamstown, Victoria (3016), within the Hobsons Bay local government area. It caters for students from Prep to 6 and in 2025 enrolled 263 students (131 girls and 132 boys). The school is affiliated with Victorian Catholic Education Authority.
St Mary's School has an ICSEA value of 1107, indicating very high socio-educational advantage. That places it in the 86th percentile of Australian schools. 40% of students come from the top socio-educational quarter and 3% from the bottom quarter.
The school employs 24 teachers (18.2 full-time equivalent) and 12 non-teaching staff, giving a student-to-teacher ratio of about 14.5 to 1. Enrolments have fallen by 22% over the past five years.
On the Success Index, St Mary's School scores 65.8 out of 100, placing it in the top 25% of primary schools nationally and 507th of 1,290 primary schools in VIC (15th of 20 in the Hobsons Bay area).
Success Index breakdown
Each component is a percentile against schools of the same type across Australia.
- Socio-educational advantage (ICSEA) (50%)ICSEA 1107
- Students in the top advantage quarter (15%)40% of students
- Teacher resourcing (students per teacher) (15%)14.5 students per teacher
- Enrolment growth vs local area (5 years) (10%)-22% enrolments since 2020 (area median -3%)
- ICSEA trend (5 years) (10%)-29 ICSEA points since 2020
The Success Index summarises the academic environment of a school community using official ACARA data. It is not a measure of teaching quality or student results. Read the methodology.
Student profile
Distribution of students across socio-educational advantage (SEA) quarters, plus community characteristics.
Enrolments by year level
How St Mary's School's 263 students are spread across year levels in 2025.
Enrolment trend
How enrolments at St Mary's School have changed over the past decade.
Free academic assessment
Is your child on track at St Mary's School?
Rankings tell you about a school community. A free Success Tutoring assessment tells you about your child: exactly where they are in English and Maths, where the gaps are, and a plan to close them. Small-group, Australian-curriculum tutoring with no lock-in contracts.
- Personalised learning plan mapped to the Australian Curriculum
- English & Maths from Kindergarten to Year 12
- Flexible memberships, no lock-in contracts
- Your nearest centre: Success Tutoring Docklands
Schools near St Mary's School
Closest schools by straight-line distance, with their Success Index.
Williamstown Primary School
Williamstown · Government primary · Prep-6
460 students · ICSEA 1123 · 114 m away
Newmark Primary
Williamstown · Independent primary · Prep-6
131 students · ICSEA 1134 · 375 m away
Williamstown High School
Williamstown · Government high school · 7-12
1,527 students · ICSEA 1112 · 513 m away
Williamstown North Primary School
Williamstown · Government primary · Prep-6
601 students · ICSEA 1135 · 1.2 km away
Bayside P-12 College
Williamstown · Government combined · Prep-12
958 students · ICSEA 1006 · 1.5 km away
Sacred Heart School
Newport · Catholic primary · Prep-6
297 students · ICSEA 1126 · 3.1 km away
Newport Lakes Primary School
Newport · Government primary · Prep-6
566 students · ICSEA 1126 · 3.4 km away
Newport Gardens Primary School
Newport · Government primary · Prep-6
516 students · ICSEA 1106 · 3.6 km away
Australian Islamic Centre College
Newport · Independent primary · Prep-6
151 students · ICSEA 1032 · 3.8 km away
Spotswood Primary School
Spotswood · Government primary · Prep-6
289 students · ICSEA 1117 · 4.0 km away
Similar schools
Catholic primary schools in VIC with a comparable ICSEA.
St Patrick's School
Geelong West · Catholic primary · Prep-6
418 students · ICSEA 1107
Our Lady of the Assumption School
Cheltenham · Catholic primary · Prep-6
257 students · ICSEA 1107
Holy Spirit School
Thornbury · Catholic primary · Prep-6
129 students · ICSEA 1107
St Louis de Montfort's School
Aspendale · Catholic primary · Prep-6
594 students · ICSEA 1107
St Joseph's School
Beechworth · Catholic primary · Prep-6
69 students · ICSEA 1106
St John Bosco's School
Niddrie · Catholic primary · Prep-6
413 students · ICSEA 1108
Frequently asked questions
Is St Mary's School a public or private school?
St Mary's School is a Catholic school, which makes it a non-government (private) school affiliated with Victorian Catholic Education Authority.
What year levels does St Mary's School offer?
St Mary's School offers Prep to 6. It is classified by ACARA as a primary school.
How many students attend St Mary's School?
In 2025, St Mary's School had 263 enrolled students (131 girls, 132 boys), a change of -22% over five years.
What is the ICSEA of St Mary's School?
St Mary's School has an ICSEA (Index of Community Socio-Educational Advantage) of 1107. The national average is 1000, so this indicates very high socio-educational advantage. ICSEA reflects the school community, not teaching quality.
How does St Mary's School rank in VIC?
St Mary's School ranks 507th of 1,290 primary schools in Victoria on the Success Index (65.8/100), and 1398th of 4,908 nationally.
What is the student-to-teacher ratio at St Mary's School?
St Mary's School has about 14.5 students per full-time-equivalent teacher, based on 2025 ACARA staffing data.
How many students start Prep at St Mary's School each year?
In 2025, St Mary's School had 41 students in Prep and 33 in Year 6.
Is St Mary's School co-ed?
Yes. St Mary's School is a co-educational school enrolling both girls and boys.
What other schools are near St Mary's School?
There are 10 other schools within 15 km of St Mary's School in our database. Scroll up to the "Nearby schools" section to compare them by Success Index, ICSEA and enrolments, or use the Compare tool.
Where can I get tutoring near St Mary's School?
The closest Success Tutoring centre is Success Tutoring Docklands, about 6.7 km from the school. Success Tutoring offers a free academic assessment to identify your child's strengths and learning gaps before any sessions begin.