Erasmus Hall High School was a four-year public high school located at 899–925 Flatbush Avenue between Church and Snyder Avenues in the Flatbush neighborhood of the New York City borough of Brooklyn. It was founded in 1786 as Erasmus Hall Academy, a private institution of higher learning named for the scholar Desiderius Erasmus, known as Erasmus of Rotterdam, a Dutch Renaissance humanist and Catholic Christian theologian. The school was the first secondary school chartered by the New York State Regents. The clapboard-sided, Georgian-Federal-style building, constructed on land donated by the Flatbush Reformed Dutch Church, was turned over to the public school system in 1896.

Around the start of the 20th century, Brooklyn experienced a rapidly growing population, and the original small school was enlarged with the addition of several wings and the purchase of several nearby buildings. In 1904, the Board of Education began a new building campaign to meet the needs of the burgeoning student population. The Superintendent of School Buildings, architect C. B. J. Snyder, designed a series of buildings to be constructed as needed, around an open quadrangle, while continuing to use the old building in the center of the courtyard. The original Academy building, which still stands in the courtyard of the current school, served the students of Erasmus Hall in three different centuries. Now a designated New York City Landmark and listed in the National Register of Historic Places, the building is a museum exhibiting the school's history.

Due to poor academic scores, the city closed Erasmus Hall High School in 1994, turning the building into Erasmus Hall Educational Campus and using it as the location for five separate small schools.