Hilary Erhard Duff is an American actress, businesswoman, singer-songwriter, producer, and writer. Duff began her acting career at a young age and quickly became labeled a teen idol as the title character of the television series Lizzie McGuire (2001–2004) and in the theatrical film based on the series, The Lizzie McGuire Movie (2003). Thereafter, she appeared in numerous films, with leading roles in Cadet Kelly (2002), Agent Cody Banks (2003), Cheaper by the Dozen (2003), A Cinderella Story (2004), and Cheaper by the Dozen 2 (2005). She later began appearing in independent films playing a wider range of roles, such as a promiscuous popstar in War, Inc. (2008), a suicidal and rebellious teenager in According to Greta (2009), and as the dramatic title character in the controversial The Haunting of Sharon Tate (2019). She has also executive produced several of the projects she starred in, such as According to Greta, Beauty and the Briefcase (2010) and The Haunting of Sharon Tate. From 2015 until 2021, she starred as Kelsey Peters on TV Land's longest-running original comedy-drama series Younger, for which she has received nominations for People's Choice Awards in 2016 and 2017.