What Are the Biggest High Schools in the USA? 75 of the Largest U.S. High Schools

By Theresa Holland

There are a number of ways to rank high schools—sports, academics, college acceptance rates, you name it. But what about the sheer size of the student body?

The largest U.S. high schools have a student population of over 5,000, and dozens more are upwards of 3,000 to 4,000. Whether you graduated from one of these schools or are just fascinated by how incredibly gigantic some of them are, you’re in the right place.

Excluding online schools and adult education centers, we’re rounding up a comprehensive list of the largest high schools in America. Check out the current top 10, see if your own school made the list, and learn where the leading 75 are located throughout the country.

Top 10 Largest U.S. High Schools

How many students go to the biggest high schools? A lot. Some of these schools have higher enrollment than many colleges and universities in the U.S.

These are the 10 biggest high schools in America based on student enrollment data from the National Center for Education Statistics (NCES) for the 2024-25 academic year:

• Brooklyn Technical High School in Brooklyn, New York
• Allen High School in Allen, Texas
• Carmel High School in Carmel, Indiana
• Conroe High School in Conroe, Texas
• Reading Senior High School in Reading, Pennsylvania
• Brentwood High School in Brentwood, New York
• Granada Hills Charter in Los Angeles, California
• Broken Arrow High School in Broken Arrow, Oklahoma
• Cypress Bay High School in Weston, Florida
• Adlai E. Stevenson High School in Lincolnshire, Illinois

See what the student population is for the top 10 largest U.S. high schools, and find out what makes them unique.

#10 Adlai E. Stevenson High School

Student population: 4,614

Student-to-teacher ratio: 16.38:1

Number of alumni on Classmates®: 10,533  

Named after Illinois’s 31st governor, Adlai E. Stevenson High School in Lincolnshire, Illinois, has a student body of over 4,500. Though the village of Lincolnshire only has a population of around 8,000, the school enrolls students from 16 communities across a sweeping 42-square-mile district. For such a large school, Stevenson High has a really decent student-to-teacher ratio of about 16 to 1.

#9 Cypress Bay High School

Student population: 4,632

Student-to-teacher ratio: 24.51:1

Number of alumni on Classmates: 2,868

Cypress Bay High School is a four-year public high school in the master-planned community of Weston, Florida, a suburb of Fort Lauderdale. It enrolls just over 4,600 students, with a student-to-teacher ratio of about 25 to 1. Cypress Bay High stands out for offering a wide range of competitive extracurriculars, including over 15 sports, almost 70 student clubs, and an exclusive Cyber STEM program in partnership with the FBI.

#8 Broken Arrow High School

Student population: 4,672

Student-to-teacher ratio: 19.52:1

Number of alumni on Classmates: 19,172

Broken Arrow High School is the eighth-largest high school in America. It’s located in Broken Arrow, Oklahoma, a suburb of Tulsa and the fourth-largest city in the state. Even though BAHS only enrolls grades 10 through 12, the student population is nearing 4,700—that’s an average of close to 1,600 per graduating class. And over 19,000 alumni from this school are on Classmates®.

#7 Granada Hills Charter

Student population: 4,701

Student-to-teacher ratio: 25.28:1

Number of alumni on Classmates: 23,935

Granada Hills Charter sits in the Granada Hills neighborhood of the San Fernando Valley in Los Angeles, California. It has a student population of roughly 4,700 and a student-to-teacher ratio of 25 to 1. Granada Hills High is ranked as one of the best schools in the state. It consistently placed in the top 200 of over 2,500 public and private high schools in California. GHC opened in 1960, and with over six decades of graduating classes, there are almost 24,000 alumni on Classmates.

#6 Brentwood High School

Student population: 4,729

Student-to-teacher ratio: 14.41:1

Number of alumni on Classmates: 20,583

The sixth-largest high school in the U.S. is Brentwood High School in the unincorporated hamlet of Brentwood on Long Island in New York. With a student body of over 4,700 and an impressive 14-to-1 student-to-teacher ratio, a vast majority of the school’s students are racial minorities or economically disadvantaged. The sprawling site has three large buildings, two auditoriums, two gyms, and six cafeterias.

#5 Reading Senior High School

Student population: 4,779

Student-to-teacher ratio: 18.85:1

Number of alumni on Classmates: 23,281

Reading Senior High School is in Reading, Pennsylvania, the state’s fourth-largest city. The school’s nickname is “The Castle on the Hill,” and if you check out photos of the stunning building, you’ll see why. Reading Senior High has a student population of close to 4,800. It opened nearly a century ago, and with almost 100 graduating classes on the books, there are over 23,000 alumni on Classmates.

#4 Conroe High School

Student population: 5,178

Student-to-teacher ratio: 16.53:1

Number of alumni on Classmates: 21,264

At number four, we’ve got Conroe High School in Conroe, Texas, which is part of the Houston–The Woodlands–Sugar Land metropolitan area. As the second-largest high school in the State of Texas, its student population is over 5,000. This school has one of the better student-to-teacher ratios of around 17 to 1. It opened in 1964, and 60 years later, more than 21,000 alumni are on Classmates.

#3 Carmel High School

Student population: 5,200

Student-to-teacher ratio: 16.85:1

Number of alumni on Classmates: 16,243

With an enrollment of 5,200, Carmel High School takes third place for the top high schools in America based on student population. It’s located in Carmel, Indiana, a suburb of Indianapolis. The enormous one-million-square-foot building sits on a 55-acre campus, boasting its own planetarium and a state-of-the-art swimming pool.

#2 Allen High School

Student population: 5,273

Student-to-teacher ratio: 24.15:1

Number of alumni on Classmates: 9,816

The second-biggest high school in America and the largest in the state of Texas is Allen High School. It’s located in Allen, a Dallas–Fort Worth metroplex suburb. Allen High opened its doors in 1910, and the school’s first graduating class of 1914 was only eight students. Over a century later, the four-year public high school has a student population of nearly 5,300.

#1 Brooklyn Technical High School

Student population: 5,808

Student-to-teacher ratio: 20.14:1

Number of alumni on Classmates: 25,026

The biggest high school in the U.S. based on student enrollment is Brooklyn Technical High School in Brooklyn, New York. But that’s not the only thing BTHS takes first place for. It’s ranked by U.S. News as the best public school in New York City, placing number one out of 533 high schools based on college prep, state testing, and graduation rates. This school is also ranked as number 71 nationwide for U.S. high school rankings.

Brooklyn Technical High has one of the highest AP participation rates, 40 athletic teams, and numerous STEM-based education programs. The colossal building was constructed in 1922 and houses New York City’s fourth-largest theater auditorium.

What is the largest high school graduating class? In 2023, the number was 1,500. BTHS currently has over 5,800 students, a student-to-teacher ratio of 20 to 1, and upwards of 60,000 alumni, over 25,000 of whom are on Classmates.

75 Biggest American High Schools

In addition to the 10 largest high schools, another 18 schools have a student population of over 4,000. The remaining 47 on our list of the 75 top high schools in the U.S. enroll more than 3,500 students.

What cities are the biggest high schools in? Many of these schools are located in urban areas or the suburbs of larger cities.

A whopping 40% (30 out of 75) of the biggest American high schools are in Texas, with six in Houston alone. This may come as no surprise from a state that prides itself on “everything being bigger.”

About 13% (10 out of 75) are located in Illinois. Around 11% (eight out of 75) are in New York, including five in Brooklyn. Florida accounts for 8% (six out of 75).

[Could do a pie chart here, but the table below should still suffice without one.]

Find Alumni and Yearbooks From Your High School

If you went to a massive high school like one of these, it might be hard to remember everyone or know whether or not a specific person attended. Or maybe your school was so big, you didn’t even know all your schoolmates by name.

While smaller schools are known for an “everybody knows everybody” vibe, the biggest high schools in the U.S. aren’t quite as intimate. But, as you can see, they often offer lots in terms of academic and extracurricular opportunities.

Searching for alumni who went to your ginormous school and need photos to jog your memory? Explore alumni records and browse digital yearbooks from your high school on Classmates! You can revisit your school’s history, see pictures from the yearbook archive, check for high school reunions, and maybe even reconnect with old schoolmates.

Search for yearbooks to get started.

Sources:

• https://nces.ed.gov/ccd/elsi/tableGenerator.aspx
• https://data.census.gov/profile?g=1600000US1743666
• https://www.usnews.com/education/best-high-schools/california/districts/granada-hills-charter-high-district/granada-hills-charter-high-school-2542
• https://www.usnews.com/education/best-high-schools/california/districts
• https://www.usnews.com/education/best-high-schools/texas/districts/allen-independent-school-district/allen-high-school-18562
• https://www.usnews.com/education/best-high-schools/pennsylvania/districts/reading-school-district/reading-senior-high-school-17296
• https://www.usnews.com/education/best-high-schools/new-york/districts/brentwood-union-free-school-district/brentwood-high-school-13532
• https://nces.ed.gov/ccd/schoolsearch/school_detail.asp?Search=1&DistrictID=3605280&ID=360528004433
• https://www.cde.ca.gov/schooldirectory/details?cdscode=19647331933746
• https://www.usnews.com/education/best-high-schools/oklahoma/districts/broken-arrow/broken-arrow-high-school-155882
• https://www.usnews.com/education/best-high-schools/new-york/districts/new-york-city-public-schools/brooklyn-technical-high-school-13269
• https://www.usnews.com/education/best-high-schools/rankings-overview
• https://bthsalumni.org/brooklyn-tech-mints-1500-new-alumni/
• https://www.usnews.com/education/best-colleges/slideshows/a-look-at-some-of-the-smallest-u-s-colleges

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