Enthiran (transl. Robot) is a 2010 Indian Tamil-language science fiction action film written and directed by Shankar. It is the first instalment in the Enthiran film series. The film stars Rajinikanth, who plays a dual role as a scientist and the robot alongside Aishwarya Rai Bachchan in the lead roles with Danny Denzongpa, Santhanam and Karunas in supporting roles. The soundtrack album and background score were composed by A. R. Rahman while the dialogues, cinematography, editing and art direction were handled by Madhan Karky, R. Rathnavelu, Anthony and Sabu Cyril respectively. The story revolves around the struggle of a scientist K. Vaseegaran to control his android humanoid robot named Chitti, after Chitti's software is upgraded to give it the ability to comprehend and exhibit human emotions. The project backfires when Chitti falls in love with Vaseegaran's girlfriend, Sana, and is manipulated by Bohra, Vaseegaran's teacher, into becoming homicidal.

After being stalled in the development phase for nearly a decade, the film's principal photography began in 2008 and lasted two years. The film marked the debut of Legacy Effects studio (which was responsible for the film's prosthetic make-up and animatronics) in Indian cinema. Enthiran was released worldwide on 1 October 2010. Produced by Kalanithi Maran, it was India's most expensive film up to that point.

The film received generally positive reviews upon release. Critics were particularly appreciative of Shankar's direction, storyline, Rajinikanth's performance as Chitti, music, action sequences, production values and the visual effects by V. Srinivas Mohan. Enthiran emerged as the highest-grossing Indian film of 2010. It won two National Film Awards, three Filmfare Awards, seven Vijay Awards and two Screen Awards. Enthiran was followed by a standalone sequel, 2.0, which released in late 2018.