Largest High Schools in America

High school is the only level where the federal government publishes a four-year graduation rate at scale. The 100 schools below are the largest US public high schools by total enrollment from the NCES Common Core of Data, paired with the school district\'s adjusted-cohort graduation rate from EDFacts. Researchers can pull the same fields programmatically through the Urban Institute Education Data API.

At 20,355 students, Commonwealth Charter Academy CS (Harrisburg, PA) is one of the largest schools of any kind in the country — a campus closer in scale to a small college than a typical neighborhood school. It anchors a top ten where every campus enrolls more than 6,918 students.

This page sorts schools by total enrollment as reported in the most recent NCES Common Core of Data release. We do not score, weight, or grade these schools — large enrollment is a description of campus size, not of education quality. Two equally good elementary schools can have very different enrollments because of district boundaries, building capacity, or grade-band configuration.

NCES classifies a campus as High when its lowest grade is 9 or higher. High schools are the only level where EDFacts publishes adjusted-cohort graduation rates, which track the share of 9th-grade entrants who graduate within four years.

Across the 100 high schools listed, 100 have a published EDFacts graduation rate. The median across schools with reported rates is roughly 74%, near the national norm. Schools showing a dash either sit in a district with a small graduating cohort that triggered privacy suppression or were recently reorganized.

A megaschool at the top of this list runs the daily logistics of a small city — three lunch periods, multiple gym facilities, a counselor caseload that crosses building boundaries. That scale enables an academic catalog few smaller schools can match (multiple AP languages, full IB diploma programs, deep dual-enrollment lanes with local colleges) but it also makes individual mentoring harder to maintain. Read enrollment as a description of the high-school experience, not a quality rank.

The proficiency column reports the district\'s EDFacts math and reading rate, applied uniformly to every high school in the district. A strong individual school inside a struggling district will look weaker than it is here; the inverse is also true. A few honest caveats: EDFacts proficiency and graduation rates are reported at the district level, not the individual school. We apply the district number to every school in that district so that the comparison is at least consistent — but a strong school inside a struggling district will look worse than it is, and vice versa. NCES publishes the most recent year of CCD data with about a one-year lag. Privacy suppression hides results for very small subgroups, which appears as missing data rather than zero.

Click any row to see the full school profile, including a direct link to the federal NCES School Locator entry and the EDFacts assessment file for the district.

We pull every school flagged as High in the most recent NCES CCD release, sort by total enrollment, and trim the list to the top 100. EDFacts adjusted-cohort graduation rates and proficiency rates are joined at the district level. Federal numbers are displayed as published — no normalization, no weighting, no synthetic letter grade. See the full methodology page for the complete data lineage.