Hilary Erhard Duff (born September 28, 1987) is an American actress, singer, songwriter, fashion designer, and spokesperson. She has an older sister, who is also an actress/singer, Haylie Duff.

After gaining fame for her starring role on the television show Lizzie McGuire, Duff went on to have a film career, and her most commercially successful pictures include Cheaper by the Dozen (2003), The Lizzie McGuire Movie (2003), and A Cinderella Story (2004). She reportedly earned $15 million in 2005. Duff has expanded her repertoire into pop music, with three RIAA certified-platinum albums and over 13 million albums sold worldwide, and she has launched a clothing line (Stuff by Hilary Duff) and an exclusive perfume with Elizabeth Arden.