Georgia has 2,290 public schools across 159 counties, and identifying the top five high schools requires being specific about the methodology. This ranking uses 2025 Georgia Milestones assessment data, the most recent cycle available, measuring the percentage of students meeting or exceeding grade level in math and science at each school. The Georgia state average for high school math sits at roughly 28% and for science at roughly 44%, so the schools below are outperforming the state by significant margins. All scores are pulled from each school's scores page on allk12.
#1: Gwinnett School of Mathematics, Science and Technology
Gwinnett School of Mathematics, Science and Technology (GSMST) in Lawrenceville is in a category of its own among Georgia public high schools. The school posts 99.6% science proficiency on the 2025 Georgia Milestones, the highest score of any public high school in the state on any subject in recent assessment cycles. With 1,304 students enrolled in Gwinnett County, GSMST operates as a competitive magnet school with selective admissions drawing the county's highest-achieving STEM-oriented students from across the district.
The GSMST scores page shows sustained near-perfect performance across multiple assessment cycles, and the school's reputation extends well beyond Georgia. It regularly appears in national rankings of top public high schools, produces a high rate of National Merit Scholars, and sends students to selective colleges at a rate that competes with the state's most elite private schools. Admission requires a rigorous application process including grades, test scores, and teacher recommendations. For students who qualify, it represents the strongest academic option in public education in Georgia without qualification.
#2: McIntosh High School
McIntosh High School in Peachtree City is the most surprising entry in this ranking for families who focus primarily on the north metro Atlanta corridor. McIntosh posts 82.9% math and 80.0% science proficiency on the 2025 Georgia Milestones, the highest combined scores of any comprehensive high school in the state that doesn't use selective admissions.
The McIntosh scores page shows multi-year consistency at this level, reflecting a school that has quietly been among Georgia's strongest academic performers for over a decade without the name recognition that north Fulton and Gwinnett schools receive. McIntosh serves Fayette County, sitting roughly 30 miles south of downtown Atlanta in the Peachtree City planned community. The school benefits from a highly educated and economically stable community with deep investment in school quality. Its position in south metro Atlanta means families seeking elite public school access at lower housing cost than the north Fulton or north Gwinnett corridors should take it seriously.
#3: Lambert High School
Lambert High School in Suwanee posts 75.8% math and 89.3% science on the 2025 Georgia Milestones with 3,249 students enrolled, making it the largest school in this ranking and one of the most impressive large high schools in the Southeast. Lambert's science proficiency of 89.3% is the highest of any comprehensive high school in Georgia on that measure, and its math proficiency of 75.8% places it comfortably in the top tier of the state's public schools.
The Lambert scores page shows sustained top-tier performance across multiple assessment years, and the school's reputation is well-established in Forsyth County as the premier public high school in a county that is itself one of the strongest school markets in Georgia. Lambert serves the southern Forsyth County corridor including portions of Suwanee and the communities along GA-400, and some Johns Creek addresses in northern Fulton County feed here rather than to Fulton County's own campuses. For a school of its size, Lambert's sustained academic performance is exceptional.
#4: Denmark High School
Denmark High School in Alpharetta posts 73.5% math and 84.6% science on the 2025 Georgia Milestones with 2,527 students enrolled. Denmark is a newer school in the north Fulton County cluster, opening in 2012, and has quickly established itself as one of the top comprehensive high schools in the state. The Denmark scores page shows consistent performance in the mid-70s for math and mid-80s for science, reflecting the demographics of the newer master-planned development in the northwestern Alpharetta and Milton corridor that the school serves.
Denmark sits within Fulton County Schools and is one of five north Fulton high schools that collectively represent the most concentrated cluster of high-performing public schools in metro Atlanta. Of those five, Denmark consistently leads on combined math and science metrics. Families relocating to north Fulton who specifically seek the strongest academic campus should prioritize addresses in the Denmark attendance zone.
#5: Lassiter High School
Lassiter High School in Marietta posts 72.1% math and 80.1% science on the 2025 Georgia Milestones with a strong academic reputation built over several decades in east Cobb County. Lassiter is the academic anchor of the east Cobb corridor that includes Walton High School, and the two schools together represent the strongest academic cluster in Cobb County Schools.
The Lassiter scores page shows sustained top-quartile performance across multiple assessment cycles. Lassiter serves the East Cobb communities along Johnson Ferry Road and the surrounding area, which has maintained a high-income and highly educated demographic profile that supports strong school outcomes. East Cobb, while often overlooked in favor of north Fulton and north Gwinnett in the metro Atlanta school conversation, delivers school quality that competes directly with those corridors at somewhat lower housing costs than the Alpharetta and Johns Creek markets.
Honorable Mentions
Several schools just outside this top five deserve recognition. Johns Creek High School in Johns Creek posts 73.8% math and 79.9% science, essentially tied with Lassiter in this ranking and by some measures the stronger school. Walton High School in Marietta posts 70.7% math and 85.4% science, with a particularly strong science score that would rank it third on that measure alone. Chattahoochee High School in Alpharetta posts 71.9% math and 81.1% science. Creekview High School in Canton posts 65.8% math and 89.0% science, the latter figure competitive with Lambert's science score, making it an underrated option in Cherokee County. South Forsyth High School in Cumming posts 66.3% math and 89.8% science, with science proficiency that ranks among the highest in the state.
What These Rankings Tell You and What They Don't
A top-five list built on state assessment scores captures something real about academic outcomes at each school. Georgia Milestones measures whether students are meeting grade-level standards in core academic subjects, and consistent performance well above state averages across multiple years is a reliable signal of a strong academic environment.
What the rankings don't capture is fit. A highly competitive STEM-focused magnet like GSMST is an exceptional school for students who thrive in that environment and a poor fit for students who don't. A large school like Lambert that serves 3,249 students offers something fundamentally different in terms of school culture and social experience from a smaller school like McIntosh or Johns Creek High. The best school for your child depends on what your child needs, not just on which campus posts the highest aggregate proficiency percentage.
The rankings also don't capture what happens below the high school level. A family that moves to the Fayette County for McIntosh should research the feeder schools that prepare students for McIntosh, because the elementary and middle school experience shapes how ready students are to perform at the high school level. Browse all schools by county across Georgia on allk12, look up scores pages for both the high schools and their feeder schools, and read the discussion boards to understand what the full K-12 experience looks like in each community.
