Madelaine Grobbelaar Petsch (born August 18, 1994) is an American actress and YouTube personality. She is known for portraying Cheryl Blossom on The CW television series Riverdale and Marissa in F the Prom.
Petsch was born on August 18, 1994 in Port Orchard, Washington. At the age of three, she began dance classes, and two years later enrolled in theater classes. 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. She attended the Tacoma School of the Arts and relocated to Los Angeles after graduating. Petsch has one brother.
Petsch appeared in a national advertising campaign for Coca-Cola in 2014. In February 2016, she was cast as Cheryl Blossom in The CW's Riverdale, having been pinned for the role since late 2015 after meeting the casting director, who was at the time working on Legends of Tomorrow. The series began filming in September of that year and premiered on January 26, 2017. In March 2017, she joined the cast of the film Polaroid, which was released in 2019.