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 Stats (2025)
- 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:
School Overview
Religious Affiliation
Grades Offered
Grades 9-12
Year Founded
1918
Colors
White, Navy Blue
First Day of School
Mon. Sep 1, 2025
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.: 13:1
Average Class Size
15 students
Number of AP Courses
34 courses
Tuition and Acceptance Rate
Admission Deadline
None / Rolling
Yearly Tuition Cost
$17,100
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
June 13, 2025 (Friday)
School Closed
June 19, 2025 (Thursday)
School Closed
June 27, 2025 (Friday)
School Closed
July 04, 2025 (Friday)
School Closed
July 18, 2025 (Friday)
School Reviews
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