Jessica Randolph Harper (born October 3, 1949) is an American actress and singer. Harper began her feature film career with a starring role in Brian De Palma's Phantom of the Paradise (1974), and subsequently featured in films including Love and Death (1975), Inserts (1975), and My Favorite Year (1982). She is best known for her portrayal of Suzy Bannion, the protagonist of Dario Argento's cult classic Suspiria (1977), and appeared in a supporting role in Luca Guadagnino's 2018 remake.

Her other films include Stardust Memories (1980), Shock Treatment (1981) (the followup to The Rocky Horror Picture Show in which she replaced Susan Sarandon as Janet Weiss), Pennies from Heaven (1981), The Blue Iguana (1988), Safe (1995), Minority Report (2002), Bones and All (2022) and Nightbitch (2024). In addition to acting, Harper is also an author of children's music and books.