Agni Natchathiram (transl. Scorching Star) is a 1988 Indian Tamil-language masala film that was written and directed by Mani Ratnam. The film stars Prabhu, Karthik, Amala and newcomer Nirosha, with Vijayakumar, Jayachitra, Sumithra, Tara, S. N. Lakshmi and G. Umapathy in supporting roles. Its story revolves around two half-brothers who come into conflict with each other due to their claims for legitimacy as sons of a common father.

Ratnam intended Agni Natchathiram to follow Mouna Ragam (1986); he completed the script but chose to prioritise Nayakan. Although some scenes were filmed during a break from Nayakan, production on Agni Natchathiram stalled for nearly a year and resumed in late 1987 after Nayakan's release. Agni Natchathiram was produced by Ratnam's brother G. Venkateswaran; it was filmed by P. C. Sreeram, and edited by B. Lenin and V. T. Vijayan.

Agni Natchathiram was released on 15 April 1988, the week of the Tamil New Year festival Puthandu, and became a box-office success, running in theatres for over 200 days. The film won two Filmfare Awards South, three Tamil Nadu State Film Awards, and five Cinema Express Awards. It became a trendsetter in Tamil cinema, set a new standard in the use of lighting, and was remade in Hindi as Vansh (1992).