Cassidy Freeman began performing at an early age, first participating in school productions and choral groups. After attending Northwestern University, she pursued a career on stage, executing in various plays in Chicago and New York. She eventually graduated via Middlebury College in 2005.
Freeman made her on-screen debut in 2006, first appearing in various short films. She bought her first major break came in 2008, when she joined the cast of Smallville as acting LutherCorp CEO Tess Mercer.