Serving 518 students in grades 9-12, Haddam-killingworth High School ranks in the top 30% of all schools in Connecticut for overall test scores (math proficiency is top 30%, and reading proficiency is top 30%).
The percentage of students achieving proficiency in math is 55-59% (which is higher than the Connecticut state average of 41%). The percentage of students achieving proficiency in reading/language arts is 70-74% (which is higher than the Connecticut state average of 50%).
The student-teacher ratio of 10:1 is lower than the Connecticut state level of 12:1.
Minority enrollment is 12% of the student body (majority Hispanic and Asian), which is lower than the Connecticut state average of 53% (majority Hispanic).
Quick Facts (2026)
- Grades: 9-12
- Enrollment: 518 students
- Student-Teacher Ratio: 10:1
- Minority Enrollment: 12%
- Graduation Rate: ≥95% (Top 10% in CT)
- Overall Testing Rank: Top 30%
- Math Proficiency: 55-59% (Top 30%)
- Reading Proficiency: 70-74% (Top 20%)
- Science Proficiency: 45-49% (Btm 50%)
- Source: National Center for Education Statistics (NCES), CT Dept. of Education
Top Rankings
Haddam-killingworth High School ranks among the top 20% of public schools in Connecticut for:
Category
Attribute
Reading/Language Arts Proficiency
Graduation Rate
School Overview
Haddam-killingworth High School's student population of 518 students has declined by 15% over five school years.
The teacher population of 51 teachers has declined by 5% over five school years.
Grades Offered
Grades 9-12
(Supplemental Virtual)
(Supplemental Virtual)
Total Students
518 students
Gender %
Total Classroom Teachers
51 teachers
Year Founded
1966
School Calendar
Last Day of School
Thu. Jun 11, 2026
School Rankings
Haddam-killingworth High School ranks within the top 30% of all 939 schools in Connecticut (based off of combined math and reading proficiency testing data).
The diversity score of Haddam-killingworth High School is 0.22, which is less than the diversity score at state average of 0.68. The school's diversity has stayed relatively flat over five school years.
Overall Testing Rank
#221 out of 939 schools
(Top 30%)
(Top 30%)
Math Test Scores (% Proficient)
55-59%
41%
Reading/Language Arts Test Scores (% Proficient)
70-74%
50%
Science Test Scores (% Proficient)
45-49%
47%
Student-Teacher Ratio
10:1
12:1
American Indian
n/a
n/a
Asian
3%
5%
Hispanic
4%
31%
Black
2%
12%
White
88%
47%
Hawaiian
n/a
n/a
Two or more races
3%
5%
All Ethnic Groups
Graduation Rate
≥95%
89%
Eligible for Free Lunch
11%
37%
Eligible for Reduced Lunch
3%
6%
School Statewide Testing
School District Name
Source: National Center for Education Statistics (NCES), CT Dept. of Education
School Notes
- School Mascot: Cougars
Frequently Asked Questions
What is Haddam-killingworth High School's ranking?
Haddam-killingworth High School is ranked #221 out of 939 schools, which ranks it among the top 30% of public schools in Connecticut.
What percent of students have achieved state testing proficiency in math and reading?
55-59% of students have achieved math proficiency (compared to the 41% CT state average), while 70-74% of students have achieved reading proficiency (compared to the 50% CT state average).
What is the graduation rate of Haddam-killingworth High School?
The graduation rate of Haddam-killingworth High School is 95%, which is higher than the Connecticut state average of 89%.
How many students attend Haddam-killingworth High School?
518 students attend Haddam-killingworth High School.
What is the racial composition of the student body?
88% of Haddam-killingworth High School students are White, 4% of students are Hispanic, 3% of students are Asian, 3% of students are Two or more races, and 2% of students are Black.
What is the student-teacher ratio of Haddam-killingworth High School?
Haddam-killingworth High School has a student ration of 10:1, which is lower than the Connecticut state average of 12:1.
What grades does Haddam-killingworth High School offer ?
Haddam-killingworth High School offers enrollment in grades 9-12 (Supplemental Virtual).
What school district is Haddam-killingworth High School part of?
Haddam-killingworth High School is part of Regional School District 17.
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