Panabaker has guest-starred in several television dramas and soap operas. She portrayed "Alice Brand" in 7th Heaven; "Melissa Rue" in ER; "Sara" in Port Charles; "Carrie Bauer" in The Brothers García; "Ellisha" in Medium; "Lindsey Willows" in CSI: Crime Scene Investigation; to name a few. In film, she appeared in Dead Heat as "Sam LaRoche"; and did some voice work in the Disney/Pixar film, Monsters, Inc.. Panabaker's breakout role came when she starred in The WB's Summerland as "Nikki Westerly", in the 2004-2005 season. She also appeared as "George" in the 2007 Nancy Drew: The Mystery in Hollywood Hills alongside Emma Roberts and Amy Bruckner.

Panabaker had a recurring role in Phil of the Future as strait-laced Debbie Berwick, a friend of, and foil to, Pim Diffy (played by Amy Bruckner). She starred in Life Is Ruff as "Emily Watson" alongside Kyle Massey and Mitchel Musso. In July of 2006 she starred in the Disney Channel Original Movie Read It and Weep (based on the book How