3 is a 2012 Indian Tamil-language romantic psychological thriller film written and directed by Aishwarya R. Dhanush, the Ex wife of the actor Dhanush, who also produced the film, thus making their debut in both the fields. He also played the male lead role alongside Shruti Haasan, whilst Sivakarthikeyan and Sunder Ramu appear in prominent roles. The film follows Ram (Dhanush) and Janani (Shruti Haasan), two intermediate sweethearts who eventually get married. However, Janani is mystified when Ram commits suicide all of a sudden and she tries to find out the truth behind his death.

The film was launched on 5 August 2011 in Chennai, with Dhanush and Amala Paul in lead roles, the latter was replaced by Shruti Haasan, due to schedule conflicts. The cinematography was handled by Velraj and editing was done by Kola Bhaskar. The soundtrack album and background score were composed by Dhanush's cousin-in-law Anirudh Ravichander, marking his debut as a composer with lyrics written by Dhanush, received positive reviews upon release. The song "Why This Kolaveri Di" penned and sung by Dhanush, became one of the most streamed songs of all time and was also listed as one of the "Recently Most Popular (Gold) Videos" on YouTube.

The film was released worldwide on 30 March 2012, with mostly positive reviews, praising the performances of Dhanush and Shruti, Anirudh's soundtrack and score, but criticizing the narration of the film. The film won three Filmfare Awards for Best Actor and Best Male Playback Singer for Dhanush, and Best Music Director for Anirudh Ravichander. Dhanush won three awards, Best Actor, Best Lyricist, and Best Male Playback Singer at the 2nd South Indian International Movie Awards. Following the success of the song "Why This Kolaveri Di", Dhanush was invited by Former Prime Minister Dr. Manmohan Singh as a Guest of Honour.