Petsch was born on August 18, 1994, and grew up in Port Orchard, Washington.[3][4][5][6] At the age of three, she developed a passion for dance and began dance classes, theatre classes followed two years later. Petsch's parents are from South Africa, and she spent the first ten years of her life dividing her time between South Africa and Washington.[7][8] Petsch experienced bullying as a child due to her natural red hair, South African accent, and being raised with no religion.[9] She attended South Kitsap High School[10] and Tacoma School of the Arts and relocated to Los Angeles immediately after graduating.[11][12] Petsch has one brother.[13]