The Brearley School is an American all-girls private school on the Upper East Side of Manhattan, New York City. It educates approximately 770 girls in grades K–12, with approximately 50 to 65 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 and the nearby all-girls Chapin School, with which it shares an after-school program and some classes.