Vazhakku Enn 18/9 (transl. Case No. 18/9) is a 2012 Indian Tamil-language crime thriller film written and directed by Balaji Sakthivel, starring newcomers Sri, Urmila Mahanta, Mithun Murali and Manisha Yadav. Pre-production of film began in 2008, with the filming commencing in 2010 only, following several delays. The cinematography was handled by Vijay Milton, while guitarist R. Prasanna scored the music.

The film was released on 4 May 2012 to high critical acclaim. Its dubbed Telugu version Premalo Padithe was released on the same day in Andhra Pradesh. The film has received numerous awards and nominations and has spawned several remakes in other Indian languages: Black Butterfly in Malayalam, Case No. 18/9 in Kannada. It was also among the films shortlisted by the FFI to become India's submission for the Academy Award for Best Foreign Language Film for the year 2012.