Riverdale Country School is a co-educational, independent, college-preparatory day school in New York City serving pre-kindergarten through twelfth grade. It is located on two campuses covering more than 27.5 acres (111,000 m2) in the Riverdale section of the Bronx, New York, United States. Started as a school for boys, Riverdale Country School became fully coeducational in 1972. It currently serves 1,140 students. According to Niche's 2023 Private School Rankings, Riverdale is ranked the 2nd best private high school in New York City and the 3rd best private K-12 school in the United States.