Haylie Duff was born in Houston, Texas on February 19, 1985. Her younger sister Hilary Erhard Duff was also born in Houston, Texas on September 28, 1987. Her father Robert Erhard Duff co-owned a series of convenience stores while her mother Susan Colleen was a housewife before finding employment producing films and music. Upon taking classes to learn acting, singing, and ballet Haylie Duff along with her sister Hilary Duff were casted in theater productions of a local sort. When BalletMet staged a production of the Nutracker ballet in San Antonio, Haylie Duff and Hilary Duff were among those included in the BalletMet cast. Susan Colleen's interest in promoting Haylie Duff and Hilary Duff as both rock stars as well as actors caused her to relocate to California while Robert Duff stayed behind in Houston, Texas. Haylie Duff and her sister Hilary Duff never attended public school a day in their life and was home schooled instead. This afforded the chance to act in television commercials as well as children clothing ads.
Haylie started to make small supporting guest star roles in True Women, The Amanda Show, Boston Public, Chicago Hope, That's So Raven, Third Watch as well as her younger sister Hilary Duff's show Lizzie McGuire. It wasn't until she played the villain role in Napoleon Dynamite that her career started to take off. More guest star roles were found in American Dreams as well as a recurring role in the second season of Joan of Arcadia on 2005. 2005 to 2007 had Haylie Duff getting her first series regular role in the final two seasons of 7th Heaven (Season 10 and Season 11). She either played the lead role or a supporting role in thirty-seven other films along with her villain role in Napoleon Dynamite. She joined the cast for the Napoleon Dynamite animated cartoon which was canceled after one season in 2012. Haylie announced her engagement to marry Matt Rosenberg on April 2014 and on May 11, 2015 she gave birth to their child Ryan Ava Erhard. She recorded a few singles, sang a duet with her younger sister Hilary and cowrote a few of Hilary Duff's songs on Hilary's albums. Haylie Duff is an accomplished Internet blogger. Her Internet blog is entitled Real Girl's Kitchen and has published a companion cookbook to go along with her Internet blog.