Cassidy Caroline Butler was born in May, 2008 in Oakland, California. Her father was working for the Oakland school district and her mother was working in affordable housing. Her father was constantly filming Cassidy, so it wasn't a surprise that she expressed an interest in entertainment.
Her first big performance was at the age of six, when she entered the school talent show. She lip sang to an early MC Hammer track, with a full and enthusiastic auditorium. Subsequently she joined the Kids N Dance program in Oakland to train in theatrical productions. She also trained in Oakland's Chinatown, in the art of Shaolin Kung-Fu. During two years, she moved up seven levels, but stopped when her family relocated to Austin, Texas.
Her first year in Austin, Cassidy took classes with the Zach Theater program. However, it was her later work with the Austin Film Festival that led her to realize a preference in acting for the camera. She took classes at the Carol Hickey Acting Studio, with emphasis on film acting. Cassidy began working in short college films at the University of Texas. Her first big performance was in the Texas Mermaid Movie as Katie, a girl coping with the loss of her mother and reuniting with an estranged father. This led to her first feature length film, working with Wendy McColm on her film Fuzzy Head.