Sir is a 2023 Indian period action drama film written and directed by Venky Atluri. The film was shot simultaneously in Telugu and Tamil with the latter titled as Vaathi and produced by Sithara Entertainments and Fortune Four Cinemas. The film features Dhanush and Samyuktha in primary roles along with P. Sai Kumar, Tanikella Bharani, Samuthirakani and Hyper Aadi.

In the small town of Siripuram/Sozhavaram in the 1990s, Thirupathi/Srinivas Tripathi is the owner of private colleges, who adopts some government colleges and sends some of his faculty members as the latter knows that his faculty members aren't capable to teach students and wants to eliminate all public institutions of intermediate college education and force students into his private institutions. However, Bala Gangadhar Tilak/Balamurugan, a qualified teacher thwarts Tripathi/Thurupathi's plans by making the students at Siripuram/Sozhavaram government college get first class. This news enrages Tripathi/Thirupathi, who reprimands and challenges Bala Gangadhar Tilak/Balamurugan to make the students secure EAMCET/TNPCEE ranks. Balu accepts the challenge and soon starts to prepare the students.