Horace Greeley High School is a public, four-year secondary school serving students in grades 9–12 in Chappaqua, New York, United States. It is part of the Chappaqua Central School District. It is consistently ranked among the top high schools in America. In 2015 it was listed as the #1 best public high school in the US by Best Colleges, and the #17 Smartest Public High School in the US by Business Insider.