[4][5] Bharathi, a young journalist, and her two friends investigate a series of terrorist attacks which have taken place in Chennai and also other illegal activities like human trafficking.

One night, Bharathi and her friends are caught video-recording illicit activities happening in a secluded house by a group of thugs, where they attempt to flee from them.

Bharathi comes up with a new idea to eradicate society's evils by creating and propagating a fictional character called Velayudham (after seeing Lord Muruga's temple nearby) who wants to clean up the city of terrorism and other illegal activities.

At the Chennai Egmore railway station, Velu's handbag is stolen by a petty thief named Speedu.

In the avatar of Velayudham, Velu starts to eradicate society's evils among others, where he soon gains wide support and acceptance among the public and police.

Ulaganathan allowed Ibrahim to carry out terrorist attacks in exchange for profits and also even tries to gain popularity by claiming Velayudham as his idea.

Ulagananthan plans to reveal Ibrahim as Velayudham's real identity in a function at the Nehru Stadium, Chennai.

The film was launched on 15 July 2010 at Madras University campus with Vijay and Hansika Motwani in the lead roles.

Sayaji Shinde, Vineet Kumar, and Abhimanyu Singh were selected to play negative roles in the film.

[22] A song sequence choreographed by Shobi that was originally to be shot in Switzerland was canned in Srinagar, Jammu and Kashmir with Genelia and Hansika filming alongside Vijay.

[33] Another reported influence for the film was the superhero costume worn by Vijay's character, which was believed to have been borrowed from the Assassin's Creed video game series, bearing a resemblance to the robes of young Altaïr, one of the protagonists in the series, leading to criticism of the film being "copied" from the video game.

Sudhish Kamath compared Velayudham to the Pink Panther films for featuring a series of "unintentional world-saving incidents.

"[34][37] The soundtrack and background score are composed by Vijay Antony with lyrics written by Annamalai, Priyan, Viveka and Siva Shanmugam.

[38] The album consisted of six tracks and was released by Sony Music India on 28 August 2011 at CSI Grounds in Madurai.

[41] Velayudham was initially supposed to be released on 22 June 2011, coinciding with Vijay's birthday, but was postponed due to a delay in production.

[44] In the United Kingdom, the film was sent for censor certification and with a running time of 117 minutes, received a 12A classification from the British Board of Film Classification, but the distributor added extra 22 minutes of uncensored footage for theatrical release, eventually resulting in all show cancellations at Cineworld.

Sify gave 4/5 stars and called it a good value for the money ("paisa vassol"), stating that the film was a "perfect outing with family, but [is] far too long.

"[54] Indiaglitz labelled it a "racy entertainer this Deepavali season" and cited it was a "right choice for the festival mood.

"[57] Similarly Oneindia gave 4/5 stars and described it as a "complete masala entertainer", highlighting its story and "amazing action sequences.

"[60] The Hindu stated that the film "simply enters and entertains" and that Raja had "churned out reasonably engaging fare", adding that it had a "strong story, a neat screenplay arresting action, admirable dance movements, one or two hum-worthy numbers and the ever-helpful sister sentiment.

[76][77] Velayudham was a relatively high grosser in Europe and North America with Taran Adarsh highlighting that the film was "rocking internationally.