Kadhalil Vizhunthen (transl. I Fell in Love) is a 2008 Indian Tamil-language romantic psychological thriller film written and directed by P. V. Prasath starring Nakul and Sunaina. The film has music by Vijay Antony, cinematography by S.D. Vijay Milton and editing by V. T. Vijayan. The shooting for the film started in August 2007, and the film was released in September 2008.

The song "Nakka Mukka", a kuthu (folk) song and "Thozhiya", a melodious romantic song, were very successful hits composed were one of the main reasons for the film's success. All songs in this movie was composed by Vijay Antony except "Unakena Naan". It was composed by this movie Director PV Prasath itself. The film was remade into Odia as Diwana (2010). "Nakka Mukka" was played in the opening ceremony of the Cricket World Cup 2011 held at Mirpur, Bangladesh. It also featured among a medley of Tamil songs performed by Shah Rukh Khan and Shriya Saran in the inaugural of the fourth edition of the Indian Premier League 2011 held in Chennai, India.