Bayam Ariyaan (transl. One who knows no fear) is a 2010 Indian Tamil-language action drama film directed by Prathesh. The film stars newcomer Mahesh Raja and Udhayathara, with Kishore, Manikandan, Saranya Ponvannan, Ponnambalam, Devi Kiruba, Aswathy, Kadhal Sukumar, and Kottachi playing supporting roles. It was released on 23 April 2010.

Police Inspector Mithran (Kishore) makes money on the side by hiring jobless youngsters in the area. The jobless Vinoth (Mahesh Raja), also known as Koni, along with his friends, indulges in criminal activities like extortion and rowdyism to fill the pocket of the corrupt cop Mithran. Despite his penchant for money, Mithran has a soft side: he cherishes his wife Ramya (Devi Kiruba) more than anything. Conversely, Vinoth enjoys drinking and spending time in brothels. He is cruel even to his mother Saraswathi (Saranya Ponvannan), whom he beats up, ill-treats, cheats, and robs. Vinoth then falls under the spell of the college student Nivedha (Udhayathara). He woos her in an unusual fashion, and surprisingly, she slowly falls for him too. The youngster Pazham (Manikandan) is also part of Mithran's team. He hates Vinoth and can do anything for money.

Mithran then plays a double game: he assigns Vinoth with the task of killing the local don Bobby (Ponnambalam). However, Mithran himself warns Bobby about it. Bobby tries to stab Vinoth from behind, but Vinoth shoots Bobby dead. One day, during a fight with other goons, Vinoth throws a glass bottle towards his offender, but it lands on his mother Saraswathi. The bottle cuts her throat, and she dies on the spot. Distraught by his mother's death, Vinoth feels remorseful and finally understands the value of his mother. Mithran assigned Pazham to kill the police commissioner, but he botched the mission, and Mithran gives refuge to Pazham in his home. Pazham, who was sexually aroused by Ramya, brutally rapes her and escapes from the place. A vengeful Mithran tracks down Pazham and kills him.

The police are ordered to encounter all the rowdies in the area, including Vinoth, and they shot all the rowdies. Mithran decides to kill Vinoth, but Vinoth murders him after a lengthy fight.

Director Prathesh, an erstwhile assistant to Kalanjiyam, Majith, and Kalaipuli G. Sekaran, made his directorial debut with Bayam Ariyaan under the banner Jeyamathey Pictures. Newcomer Mahesh Raja, formerly a production executive, was selected to play the hero, while Kishore and Boys fame Manikandan signed to play significant roles. Shanuja was initially chosen to play the female lead but owing the difference of opinion between her and the production unit, she was replaced by Udhayathara. The film was filmed in a cemetery in Pondicherry where the entire crew dwelled and filmed continuously.^[1][2][3][4]

The film score and the soundtrack were composed by P. C. Shivan. The soundtrack features 7 tracks with lyrics written by Mohanrajan. The audio was released on 3 December 2009 at the film chamber in Chennai by director Venkat Prabhu and Sneha. James Vasanthan, Jai, Vaibhav Reddy, and R. K. attended the function.^[5][6][7][8]

The film was released on 23 April 2010 alongside Pattu Vanna Rosavam and Rettaisuzhi.^[9]