Geraldine Viswanathan (born June 20, 1995) is an Australian actress. She gained attention in the role of Kayla in the 2018 film Blockers, for which Refinery29 referred to her as "the film's breakout star." The star attended a school of Performing Arts in Broadmeadow, Newcastle. She had previously appeared in Emo the Musical. She plays Eliza, a worker in Heaven, as a regular in the 2018 sitcom Miracle Workers, working alongside Steve Buscemi and Daniel Radcliffe. She cites the TV show Friends as an influence, with Anne Hathaway inspiring certain acting techniques.
Viswanathan's father, Suresh Viswanathan, is of Tamil descent and her mother, Anja Raith, is from Switzerland. Her first language was Tamil, but she only knows a few words of the language currently; she is fluent in Swiss German. Viswanathan has a sister, Indira.