St. Thomas the Apostle School
Diocesan school · Grades Pre-K–8
Crystal Lake, IL
265 King St, Crystal Lake, IL 60014
Overall grade: A+
ChooseAPrivateSchool.com grade, from official facts compared with similar schools.
- AClass size
- A-Years serving families
- B+Diversity
What stands out
- The only Catholic school in Crystal Lake
- Smaller classes than 81% of Catholic schools in Illinois
- Serving families in Crystal Lake since at least 2011
St. Thomas the Apostle School is a Catholic diocesan school in Crystal Lake, Illinois, for students from pre-K through 8th grade. It has about 164 students and around 9 students per teacher, smaller classes than 81% of Catholic elementary schools in Illinois. It has been listed in official private school records since 2011–12. The school is part of the Diocese of Rockford. Students attend about 6.5 hours a day, 176 days a year.
At a glance
- Grades
- Grades Pre-K–8
- Students
- 164
- Teachers
- 18 (full-time equivalent)
- Students per teacher
- 9.1
- Boys and girls
- Coed · 76 girls, 88 boys
- Religious affiliation
- Catholic · Diocesan school
- Diocese
- Diocese of Rockford
- School day
- About 6.5 hours
- School year
- 176 days
- Library
- Yes
Reviews
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How it compares
- Smaller classes than 81% of Catholic elementary schools in Illinois (9 students per teacher).
- A smaller school: fewer students than 56% of Catholic elementary schools in Illinois.
- Compared with 285 Catholic elementary schools in Illinois.
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. Thomas the Apostle School
What grades does St. Thomas the Apostle School serve?
St. Thomas the Apostle School serves grades Pre-K–8.
How many students attend St. Thomas the Apostle School?
About 164 students, with 9 students per teacher, according to official records.
How much is tuition at St. Thomas the Apostle 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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