Sonnal Thaan Kaadhala () is a 2001 Indian Tamil-language romantic drama film written, directed and produced by T. Rajendar, who also composed the music and stars alongside Murali, Roja, Karan, Livingston, Swathi and Vadivelu. T. Rajendar's son and actor, Silambarasan, makes a special appearance in 2 songs. The film released on 18 May 2001.
T. R. (T. Rajendar) investigates a case in which Roja (Roja) is the lead female singer. Roja works in a finance firm and has a big family of three sisters, a brother (Kuralarasan Rajendar), an alcoholic father (Manivannan), and a mother (Vadivukkarasi) to support. Murali (Murali), her office colleague, loves her and makes his intention clear in every opportunity that he gets. However, Roja has no time for him. T. R. has a sister named Saro (Swathi), who is married to a corrupt cop named Inbaraj (Karan). Inbaraj, furious about T. R. exposing him in his newspaper, harasses Saro, egged on by his avaricious mother (Y. Vijaya) and sister (Bhuvaneswari). The burden of taking care of the family becomes a little too much for Roja. Finally T. R., against all odds, advises Roja to accept Murali's love.
T. Rajender announced that his son Silambarasan would play the lead role in Kadhal Azhivathillai in 2000. After failing to find a suitable lead actress to appear opposite Silambarasan, Rajender postponed the project and started to make Sonnal Thaan Kaadhala. Bobby, actress Rajashri's sister, was cast in a leading role, but the actress opted to work on other Telugu films instead. Subsequently, her role in Sonnal Thaan Kaadhala was shortened, as Rajender continued to shoot without her.
There are eight songs composed by T. Rajendar.
Visual Dasan of Kalki wrote poignant romance, warm sentiment, menacing sets, these elements make a typical Rajender film. this one is a mixed bag which seems to have mistakenly copied his own style. Malini Mannath of Chennai Online wrote "Too many characters, and it is a hotchpotch of situations. T.Rajender's fans will be definitely disappointed!". The film also reviewed by Ananda Vikatan. It won two Tamil Nadu State Film Awards: Best Family Film and Best Child Star (Kuralarasan).