Cecily Brooke von Ziegesar (VON zig-AY-zər; born June 27, 1970) is an American author best known for the young adult novel series Gossip Girl, upon which the hit television show is based.

Born in New York City, her childhood dream was to become a ballerina; she began lessons at age 3 and auditioned for the School of American Ballet at age 8, but was rejected. As a teenager, von Ziegesar commuted to Manhattan at 6 a.m. to attend the Nightingale-Bamford School.

After graduating from Nightingale, von Ziegesar attended Colby College before spending a year in Budapest working for a local radio station. She returned to the United States to study creative writing at the University of Arizona, but dropped out shortly thereafter. Back in New York, while working, she began her career in writing.