Sattam Oru Vilaiyattu is a 1987 Tamil-language vigilante action film directed by S. A. Chandrasekhar and produced by Shoba Chandrasekhar.
The story follows Raja, who witnesses his mother and younger brother murdered when he is just a child. Years later, as an adult known as Vijay, the DCP's son, he seeks vengeance against the criminal Mathappu Sundaram.
Vijay tracks down Mathappu Sundaram and executes his revenge by killing each of the three sons involved in their parents' deaths in elaborate ways: one under water, another from a mountain peak, and the third incident is staged to look like an accident involving the car falling off the peak.
The film stars Vijayakanth, Radha, and Ravichandran. The music was composed by M. S. Viswanathan.
Sattam Oru Vilaiyattu was released on 21 October 1987.