Rockstar is a 2011 Indian Hindi-language musical romantic drama film written and directed by Imtiaz Ali. The film stars Ranbir Kapoor and Nargis Fakhri in lead roles, with Aditi Rao Hydari, Piyush Mishra, Shernaz Patel, Kumud Mishra, Sanjana Sanghi, Aakash Dahiya and Shammi Kapoor in pivotal supporting roles. The soundtrack was composed by A. R. Rahman. The film marks the posthumous screen appearance of Shammi Kapoor, following his death on 14 August 2011.

Rockstar was released worldwide in theatres on 11 November 2011. On the day of release, Tibetans in Chennai and Kangra protested against the Central Board of Film Certification, which asked the film-makers to censor scenes featuring the Tibetan flag. Made on a budget of ₹600 million (US$6.9 million), the film grossed ₹1.08 billion (US$12 million) worldwide, emerging as one of the highest-grossing films of the year, majorly appealing to the young urban crowd. It received generally positive reviews, with high praise directed towards its novel concept, story, screenplay, dialogue, soundtrack and performances of the cast, with major praise for Kapoor's central performance.

A recipient of numerous accolades, Rockstar received 10 nominations at the 57th Filmfare Awards, including Best Film, Best Director (Ali) and Best Female Debut (Fakhri), and won 5 awards, including Best Actor (Kapoor) and Best Music Director (A. R. Rahman).

Over the years, the film has gone to achieve a cult following, and its soundtrack album has often been termed as the best music album of the decade. Due to popular demand, the film was re-released on 17 May 2024 in theatres and grossed over ₹10 crore (US$1.1 million)– ₹12 crore (US$1.4 million) Following the re-release of the film in 2024, it is currently the sixth highest-grossing re-released Indian film.