St. Mary School
Parish school · Grades K–8
East Islip, NY
16 Harrison Ave, East Islip, NY 11730
Overall grade: B
ChooseAPrivateSchool.com grade, from official facts compared with similar schools.
- BClass size
- A-Years serving families
- A-Diversity
What stands out
- Serving families in East Islip since at least 2011
St. Mary School is a Catholic parish school in East Islip, New York, for students from kindergarten through 8th grade. It has about 331 students and around 16 students per teacher. Its enrollment has held steady since 2011–12. The school is part of the Diocese of Rockville Centre. Students attend about 6 hours a day, 180 days a year.
At a glance
- Grades
- Grades K–8
- Students
- 331
- Teachers
- 20.9 (full-time equivalent)
- Students per teacher
- 15.8
- Boys and girls
- Coed · 190 girls, 141 boys
- Religious affiliation
- Catholic · Parish school
- Diocese
- Diocese of Rockville Centre
- School day
- About 6 hours
- School year
- 180 days
- Library
- Yes
Reviews
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How it compares
- Larger than 90% of Catholic elementary schools in New York.
- Compared with 242 Catholic elementary schools in New York.
Students by survey year
Total students reported in official records since 2011–12.
Students by grade
Student body
Member of
- National Catholic Educational Association
Questions to ask on a tour
- What is tuition, and what does it include (books, fees, uniforms, trips)?
- Do you offer financial aid, sibling discounts or payment plans?
- Do you accept ESA, voucher or tax-credit scholarship funds?
- How big are classes in my child's grade?
- What support is there for students who need extra help or more challenge?
- Is the school accredited, and by whom?
- What do a typical day and a typical week look like?
- How does the school communicate with families?
Questions about St. Mary School
What grades does St. Mary School serve?
St. Mary School serves grades K–8.
How many students attend St. Mary School?
About 331 students, with 16 students per teacher, according to official records.
How much is tuition at St. Mary School?
Call the school to ask about tuition, financial aid and payment plans.
Official record · Updated October 2026 · Official search · Something wrong? Tell us
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