1: Nenokkadine (transl. 1: I am alone) is a 2014 Indian Telugu-language action thriller film directed by Sukumar. The film was produced by Ram Achanta, Gopichand Achanta and Anil Sunkara on 14 Reels Entertainment banner and was distributed by Eros International. The film stars Mahesh Babu and Kriti Sanon in lead roles. Nassar, Pradeep Rawat and Kelly Dorji appear in supporting roles. Mahesh Babu's son, Gautham Krishna, made his debut in the film as a younger version of the protagonist. 1: Nenokkadine revolves around the search by Gautham, a rock musician with schizophrenia, missing 25 percent of his brain's grey matter for his parents with the help of his girlfriend Sameera, a journalist.

Sukumar began working on 1: Nenokkadine's script after completing 100% Love (2011), making a bus driver's tale about a boy who claimed that his parents were murdered on his bus the film's base. R. Rathnavelu was the film's director of photography, and Karthika Srinivas, its editor. Devi Sri Prasad composed the soundtrack and background score. 1: Nenokkadine was introduced on 12 February 2012, and principal photography, which began on 23 April 2012, was completed in late October 2013. It was filmed in London, Belfast, Bangkok and Indian cities including Hyderabad, Mumbai, Goa, Chennai and Bangalore. Produced on a budget of ₹60–70 crores, it was the most expensive Telugu film at the time of its release.1: Nenokkadine was released on 10 January 2014 on about 1,500 screens during the Sankranti festival season. The film received positive reviews from critics, praising Sukumar's direction, writing, screenplay, musical score, emotional weight, cinematography, action sequences and cast performance (particularly Babu), however the complexity in screenplay and length receives mixed reception. Grossing over $1.327 million, 1: Nenokkadine became the fourth-highest-grossing Telugu film at the United States box office at the time. The film was commercially unsuccessful at the box office but has gained a cult following over the years for Babu's stellar performance and Sukumar's unique writing. The film won three awards from eight nominations at the 4th South Indian International Movie Awards, and two awards at the 11th CineMAA Awards. The film is considered one of the "25 Greatest Telugu Films Of The Decade" by Film Companion. It was dubbed in Hindi as 1: Ek Ka Dum.