Hilary Erhard Duff (born September 28, 1987) is an American actress and pop music singer. After gaining prominence in the television show Lizzie McGuire, she has since gone onto a film career, with roles in mainstream pictures such as Cheaper by the Dozen, A Cinderella Story and independent films such as Material Girls and The Perfect Man. Duff has also launched a successful music career that has yielded two number one albums in the U.S.

Hilary Duff was born in Houston, Texas as the second child of Robert Erhard Duff, owner of a chain of convenience stores, and his wife Susan Colleen Cobb, a homemaker. Duff's middle name of "Erhard" was the maiden name of her part German American paternal grandmother, Mary Erhard; Duff also has German ancestry on the part of her maternal grandmother, Amy Beulah Schlemmer. After Duff's mother encouraged her to take an acting class alongside her older sister, Haylie Duff, both girls won parts in various local theatre productions. At the age of six, the Duffs participated in the ballet The Nutcracker Suite with Columbus Ballet Met in San Antonio. The siblings became more and more enthusiastic about the idea of acting professionally, and they eventually relocated to California with their mother. Bob Duff stayed at the family home in Houston to maintain their business. Through years of auditions and meetings, both sisters managed to clinch appearances in several television commercials.