The Brearley School is an all-girls private school in New York City, located on the Upper East Side neighborhood in the borough of Manhattan. The school is divided into lower (kindergarten – grade 4), middle (grades 5–8) and upper (grades 9–12) schools, with approximately 50 to 60 students per grade.

In addition to being a member of the New York Interschool Association, Brearley is considered a sister school of the all-boys Collegiate School, the all-girls Spence School and the nearby all-girls Chapin School, with which it shares an after-school program and some classes.