Mark T. Sheehan High School
Wallingford, CT · High School · Grades 9-12
Mark T. Sheehan High School is a high school in Wallingford, CT with 722 students enrolled and a 63% proficiency rate. Part of Wallingford School District. NCES data from the U.S. Department of Education.
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About This School
Mark T. Sheehan High School is a high school located in Wallingford, Connecticut. The school serves 722 students in grades 9-12. The student-to-teacher ratio is 10.5:1.
According to EDFacts assessment data, 63% of students meet grade-level proficiency standards in combined math and reading. The school reports a 86% graduation rate.
27% of students qualify for free or reduced-price lunch.
Mark T. Sheehan High School is part of the Wallingford School District in Connecticut.
How This School Compares
Mark T. Sheehan High School has 722 students enrolled, making it larger than the average school in Wallingford School District (433 students). Its 63% proficiency rate is 6 percentage points above the district average of 57%. Compared to the Connecticut state average of 53%, the school performs 10 points higher. With a 10.5:1 student-teacher ratio, it offers smaller class sizes than the national average.
Frequently Asked Questions
Mark T. Sheehan High School has 722 students enrolled in grades 9-12. The student-to-teacher ratio is 10.5:1.
According to EDFacts data, 63% of students at Mark T. Sheehan High School meet grade-level proficiency standards in combined math and reading assessments.
Mark T. Sheehan High School has a 86% graduation rate, measuring the percentage of students who graduate within four years.
Mark T. Sheehan High School is part of the Wallingford School District in Wallingford, Connecticut. You can view all schools in this district on the district page.
All data on this page comes from the National Center for Education Statistics (NCES) Common Core of Data and EDFacts assessment results. These are official federal datasets published by the U.S. Department of Education.
School profiles are built from NCES directory data and EDFacts assessment results. Proficiency rates reflect combined math and reading performance. Graduation rates are reported for high schools with available data.
this entity is one of the data points covered by this site’s U.S. K-12 school outcomes and enrollment dataset. The detail above comes directly from NCES Common Core of Data and EDFacts; the context that follows situates the headline numbers against the broader distribution across U.S. public schools and districts.
The methodology behind every numeric value on this page is publicly documented on the NCES Common Core of Data and EDFacts portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. public schools and districts with similar size, similar exposure, or similar geography — not the national-level summary alone.
Source: NCES Common Core of Data, 2026.