Sandi Gardiner was born in Adelaide, Australia, to Carina Calo, a civil engineer, and Leonard Albert Gardiner a microbiology professor. Sandi always had a love for theater and performing and started out modeling at the age of 8 when she was scouted in her hometown by an agent. She continued to model, do commercials and have small roles in films in Australia as well as Asia and Europe, throughout high school and college before moving to Los Angeles and booking the first audition she went out on. Sandi has continued to work steadily in film and television and still resides in Los Angeles.