Kalyana Samayal Saadham (transl. Wedding Feast), also known by the initialism KSS, is a 2013 Indian Tamil-language romantic comedy film written and directed by R. S. Prasanna. It stars Prasanna and Lekha Washington, while Crazy Mohan, Delhi Ganesh, Uma appear in supporting roles. Produced by Ananth Govindan and Arun Vaidyanathan under the Everest Entertainment banner, it was distributed by Abinesh Elangovan's Abi TCS Studios, C. V. Kumar's Thirukumaran Entertainment and RPP Film Factory.

The film follows Raghu, a software engineer who faces several challenges in his arranged marriage as he suffers from erectile dysfunction and tries to find a solution to his problem. Prasanna, a gold medal winner from L. V. Prasad Film Institute, made his directorial debut through this film. Principal photography of the film started on 3 January 2013, and completed within 25 days. The music was composed by Arrora, with cinematography handled by Krishnan Vasant and editing done by Sathyaraj Natarajan.

Kalyana Samayal Saadham, was marketed as a feel-good wedding movie, with some modern twists. The film released worldwide on 7 December 2013, and received critical acclaim. It was listed on "The list of Films, that redefined Tamil cinema" by The Hindu. The film was remade in Hindi, titled as Shubh Mangal Savdhan, directed by Prasanna himself.