- Was a member of competitive cheerleading team the California Flyers.
- Attempted to launch a pop singing career in 2002 with a cover of The Partridge Family's 1970 smash "I Think I Love You."
- Modeled for clothing retailer Abercrombie & Fitch and in runway shows before moving into acting.
- Made her big-screen debut in the 2006 horror remake When a Stranger Calls.
- Had guest arcs on the CW's Supernatural and Gossip Girl before landing leading roles on the network's Melrose Place and Arrow.
- Involved in H.E.L.P. Malawi, and created the Katie Cassidy and Friends Garden when she went to visit the country.
- Dana Brunetti — Ex-significant Other
- David Cassidy — Father
- Jack Cassidy — Grandfather
- Ryan Cassidy — Uncle
- Sue Shifrin — Stepmother
- Shaun Cassidy — Uncle
- Beau Devin Cassidy — Half Brother
- Richard Benedon — Stepfather
- Evelyn Ward — Grandmother
- Sherry Benedon — Mother
- Jesse McCartney — Ex-significant Other
- Patrick Cassidy — Uncle
Season 4, Episode 5
- Birth Name: Katherine Evelyn Cassidy
- Birth Place: Los Angeles, California, United States
- Birthday: November 25, 1986, Sagittarius
- Profession: Actor, Model, Singer