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.
I februari 2016, tilldelades Petsch rollen som Cheryl Blossom i CW-dramaserien Riverdale, hon hade varit fastlagd för rollen sedan slutet av 2015 efter att ha träffat rollsättaren, som arbetade då med Legends of Tomorrow.