Diesel is a 2025 Indian Tamil-language action thriller film written and directed by Shanmugam Muthusamy in his directorial debut and produced by Third Eye Entertainment and SP Cinemas.

The film stars Harish Kalyan and Athulya Ravi in the lead roles, while Vinay Rai as its antagonist with an ensemble cast consisting of P. Sai Kumar, Ananya, Karunas, Ramesh Thilak, Kaali Venkat, Vivek Prasanna, Sachin Khedekar, Zakir Hussain, Thangadurai, and KPY Dheena in pivotal roles.

The film's music is composed by Dhibu Ninan Thomas, with cinematography handled by M. S. Prabhu and Richard M. Nathan; and editing by San Lokesh. Diesel was theatrically released on 17 October 2025, coinciding with Diwali.