Annaatthe (transl. Big Brother) is a 2021 Indian Tamil-language action thriller film directed by Siva and produced by Kalanithi Maran under the banner Sun Pictures. The film stars Rajinikanth in the titular role, alongside Khushbu, Meena, Nayanthara, and Keerthy Suresh, Jagapathi Babu, Prakash Raj, Soori, Pandiarajan, Sathyan and Sathish. D. Imman composed the film's music, Vetri handled the cinematography, Dhilip Subbarayan arranged stunts and Ruben edited the film. The movie's plot revolves around Kaalaiyan, a sarpanch (decision maker) in Thanjavur, who strives to protect his sister from a businessman and his elder brother.

The film was officially announced in October 2019, marking Rajinikanth's first collaboration with Siva. Principal photography began on 11 December 2019 and was completed in September 2021. The COVID-19 lockdown in India and Rajinikanth's health issues in late-December 2020 delayed the film's production. Filming was primarily done in Ramoji Film City, Hyderabad, and a few sequences were shot in Chennai.

Annaatthe was released on 4 November 2021, coinciding with the Deepavali festival. The movie received mixed-to-negative reviews from critics. During its theatrical run, Annaatthe grossed an estimated revenue of ₹230-240 crore worldwide against a budget of ₹180 crore. The film was also released in Argentina to promote culture and tourism.