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Largest Illinois Private Schools

Name: Illinois Average Students Per School Trends (All Private Schools)
Creator: Private School Review
License: https://www.privateschoolreview.com/terms

The average private school in Illinois has 167 students (2026-27).

The largest private school in Illinois is American School, with 6,319 students.

Quick Facts (26-27)

# IL Schools Ranked: 1,506
Top 20 Range (Students): 817–6,319
IL School Avg.: 167
National School Avg.: 175

Quick Facts (26-27)

# IL Schools Ranked: 1,506
Top 20 Range (Students): 817–6,319
IL School Avg.: 167
National School Avg.: 175

Illinois Average Students Per School (Trends)

Total Growth: (-1.2%) (-2 since 2015)

View Data

Year	National avg	Illinois (IL) avg	YoY Change (#)	YoY Change (%)
2025	179	166	▲ +4	▲ +2.5%
2024	172	162	▼ -9	▼ -5.3%
2023	174	171	▼ -7	▼ -3.9%
2022	185	178	▲ +4	▲ +2.3%
2021	180	174	▲ +6	▲ +3.6%
2020	171	168	▼ -6	▼ -3.4%
2019	175	174	▲ +3	▲ +1.8%
2018	172	171	▼ -6	▼ -3.4%
2017	180	177	▲ +2	▲ +1.1%
2016	178	175	▲ +7	▲ +4.2%
2015	167	168	—	—

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Source: National Center for Education Statistics (NCES) Private School Universe Survey (PSS), direct school submissions, and proprietary website research and analysis by Private School Review.

Note: Data may not be displayed on any public-facing website or service that replicates or resembles a school search or review portal without prior written permission. See our Terms of Service.

Show school map — Illinois (students range: 817–6,319, avg 167)

School Size Range: 713 6,319 Avg. School Size: 1,142

Frequently Asked Questions

What is the Illinois average private schools student size?

The Illinois average private schools student size is 167 for 2026-27.

What are the private schools with the largest student size in Illinois?

The top ranked private schools in Illinois include American School, University of Chicago Laboratory Schools and Loyola Academy.

What is private high school and private elementary school with the largest student size in Illinois?

The private high school with the largest student size in Illinois is American School, with a value of 6319. The private elementary school with the largest student size is American School, with a value of 6319.

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