Nenjam Marappathillai (transl. The heart never forgets) is a 2021 Indian Tamil-language horror film written and directed by Selvaraghavan. Jointly produced by Escape Artists Motion Pictures and GLO Studios, the film stars S. J. Suryah, Nandita Swetha, and Regina Cassandra. Yuvan Shankar Raja composed the film score and soundtrack, with cinematography and editing handled respectively by Arvind Krishna and Prasanna GK.

Nenjam Marappathillai began production in January 2016 and was completed in June 2016, but remained unreleased for several years, because of various consecutive issues, the first of which was the introduction of the Goods and Services Tax. After a long period of delays, it was released on 5 March 2021 and received mixed reviews from critics with praise for the performances, originality and soundtrack but criticised the climax and predictability. The film was a box office success.