Trinity High School

Trinity High School, founded in 1918 by the Dominican Sisters of Sinsinawa Wisconsin, is a Catholic college-preparatory high school for young women.
Trinity has earned an excellent reputation as a premier high school with a strong commitment to educating young women and preparing them for the future: intellectually, spiritually, socially, and morally.
The school community guides young women in developing skills for lifelong learning, an ethnic of care and the desire for excellence.
Each student is recognized as unique.  In a nurturing, catholic, college preparatory enviornment, she is encouraged to become self-directed toward responsible participation in the Christian community in order to impact society, Church and family in the twentyfirst century.

Quick Facts (2026)

  • Top-Ranked IL School
  • Grades: 9-12
  • Enrollment: 422 students
  • Yearly Tuition: $17,100
  • Average class size: 15 students
  • Application Deadline: None / Rolling
  • Source: Verified school update

Top Rankings

Trinity High School ranks among the top 20% of private schools in Illinois for:

Category
Attribute
Student Body

School Overview

Religious Affiliation
Grades Offered
Grades 9-12
Year Founded
1918
Colors
White, Navy Blue
Campus Size
small

Student Body

Total Students
422 students
Student Body Type
% Students of Color
46%
State avg.: 34%
Students by Grade

Academics and Faculty

Total Classroom Teachers
39 teachers
Student-Teacher Ratio
11:1
National avg.: 11:1
Average Class Size
15 students
Number of AP/Advanced Courses
34 courses

Tuition and Acceptance Rate

Admission Deadline
None / Rolling
Yearly Tuition Cost
Application URL

School Notes

  • School Mascot: Captain Blazer
  • Trinity High School, founded in 1918 by the Dominican Sisters of Sinsinawa Wisconsin, is a Catholic college-preparatory high school for young women. Trinity has earned an excellent reputation as a premier high school with a strong commitment to educating young women and preparing them for the future: intellectually, spiritually, socially, and morally. The school community guides young women in developing skills for lifelong learning, an ethnic of care and the desire for excellence. Each student is recognized as unique. In a nurturing, catholic, college preparatory enviornment, she is encouraged to become self-directed toward responsible participation in the Christian community in order to impact society, Church and family in the twentyfirst century.
Source: Verified school update

Frequently Asked Questions

How much does Trinity High School cost?
Trinity High School's tuition is approximately $17,100 for private students.
What is Trinity High School's ranking?
Trinity High School ranks among the top 20% of private schools in Illinois for: Largest student body and Most AP courses offered.
When is the application deadline for Trinity High School?
The application deadline for Trinity High School is rolling (applications are reviewed as they are received year-round).

School Calendar

View the Trinity High School yearly calendar below. Note key dates such as:

Event
Date
School Closed in Observance of Juneteenth
June 19, 2026 (Friday)
School Closed
June 26, 2026 (Friday)
School Closed in Observance of Independence Day
July 02, 2026 (Thursday)
School Closed
July 03, 2026 (Friday)
School Closed
July 10, 2026 (Friday)

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Quick Facts (2026)

  • Top-Ranked IL School
  • Grades: 9-12
  • Enrollment: 422 students
  • Yearly Tuition: $17,100
  • Average class size: 15 students
  • Application Deadline: None / Rolling
  • Source: Verified school update

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Did You Know?

The average private school tuition in Cook County, IL is $13,441 for elementary schools and $19,394 for high schools (read more about average private school tuition across the country).
The average acceptance rate in Cook County, IL is 83% (read more about average acceptance rates across the country).

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