Katie Cassidy was born Katherine Evelyn Anita Cassidy on November 25, 1986, in Los Angeles, California. Her father, David Cassidy, was a pop star in the 1970s. Her famous relatives include uncles Shaun Cassidy, Patrick Cassidy and Ryan Cassidy, the sons by her grandfather Jack Cassidy's marriage to Shirley Jones; Katie's grandmother was Evelyn Ward. As a child, Katie took gymnastics, studied piano, guitar and singing, then took dancing and acting lessons and eventually became a cheerleader for the California Flyers. She attended Calabasas High School in her neighborhood. For years prior to graduation in 2005, Katie was modeling and studying acting in community theater. Katie had just been accepted to 'Tisch' at NYU when she was offered her first role as "Dee Dee", which was one month before graduating. Katie has not stopped working since. Katie's early exposure to show business, the cosmopolitan culture of Los Angeles, her family upbringing, and her comprehensive education altogether produced a remarkable result. She grew up as a multifaceted person showing her many talents in a variety of professions such as recording her father's 1970s hit "I Think I Love You" and singing in VH1's TV special Bubblegum Babylon (2002), writing her own songs, modeling for Abercrombie and Fitch and Guess?'s Rock and Republic clothing lines in 2004, and acting. She met her ex-boyfriend, Jesse McCartney, there and later appeared as his love interest in his video hit "She's No You". A story on Jesse and Katie appeared in the January 2006 issue of Teen People magazine. Jesse wrote the song "Bleeding Love" performed by Leona Lewis, about Cassidy and their relationship. At that time she was busy working on five feature film productions going on almost simultaneously. Katie made several appearances in TV series, such as 7th Heaven (1996) and Sex, Love & Secrets (2005), among others. She appeared as Samantha, the grown-up daughter of Adam Sandler and Kate Beckinsale in the comedy Click (2006). After the release of a teen horror film, When a Stranger Calls (2006),in which she co-starred as Tiffany, Cassidy went to Vancouver to work on her second horror film, Black Christmas (2006), in which she stars as a sorority girl. Katie recently beat out the likes of Jessica Simpson and Kristin Cavallari for the leading role opposite John Travolta as his daughter and the heir to the most powerful energy company in the world in Dallas, the big-screen remake of the cult TV series.